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Thursday, 15 August 2019

Over the years, we’ve posted lots of helpful information on air-conditioning problems and solutions, including air flow and humidity.  In this post, we’ve assembled these helpful videos and posts in one place, to help you find the information you need more easily.  You can even download this helpful list here.

Common AC Problems

Refrigerant Leaks and Freon

Humidity and Mold

Dealing with Air Flow Issues (Uneven Cooling)

Weather Challenges

Selecting an Air Conditioning Solution

Energy Efficiency: Making the most of your AC

Latest Cooling Technologies

If you still don’t find what you’re looking for, give us a call at (615) 832-8500, and we’ll provide your problem the personal attention and professional expertise it deserves.  At Interstate AC Service, we never forget that we’re here for YOU!


Posted on 08/15/2019 7:11 AM by Tony Anderson
Monday, 15 July 2019

It’s common to have some rooms in your home that always get too hot in the summer or too cold in the winter.  In an effort to force more air into the needed room(s), you close some vents in the little-used rooms. This may seem like a good idea, but you may be doing more harm than good when you seal up or block vents.



When you close a vent register, the system keeps cooling and pumping without delivering the cool air to a usable space. You're basically paying to keep the inside of your ductwork cold!  In fact, this may lead to increased energy consumption due to increased duct leakage of conditioned air, and increased suction of unconditioned air from around doors and windows.  If the return air grate for your home is located in or near the closed off room, then you’ve really created a problem!  This can cause the compressor and condenser to cycle too frequently, and puts strain on the whole system, leading to accelerated wear and ultimately, an early failure. Plus, with the added pressure against the closed vent, it is apt to start “whistling” or making a rattling noise.  Why risk this damage when it doesn’t work and won’t even save energy? 


If you only want to keep a single room cooler or warmer, consider adding a ductless mini-split system, or adding an additional register or enlarging the existing registers in that room.  Checkout our posts about uneven heating and cooling and our 3-part video series on zoning for other possible solutions.  But the best thing would be to have a skilled HVAC technician evaluate your problem, so you’ll have confidence that the solution they propose will work… instead of spending money on things that may not.

If you live in the Nashville area and want to make sure your air-conditioning or heating system is running at peak efficiency, call on Interstate AC Service, at (615) 832-8500.  We’re here for YOU!

Posted on 07/15/2019 7:02 AM by Tony Anderson
Saturday, 15 June 2019

Have you ever wondered how your house measures up to similar houses in your area?  The Home Energy Yardstick provides an online analysis of energy use of your home compared to that of similar homes, taking into account the effects of local weather, home size, number of occupants, and your home's energy use. The “Yardstick” is a scale from 1 (poorest energy use) to 10 (best energy use). It can be applied to single−family detached homes, mobile homes, townhouses, and duplexes. Sorry, apartment data isn’t valid. The Yardstick score is based on data obtained from the U.S. Department of Energy's Residential Energy Consumption Survey (RECS). Although the Home Energy Yardstick is not meant to replace a home energy audit conducted by a professional, it can provide you some useful insights, using real-life data.

How it Works

Go to http://www.energystar.gov/yardstick and click on “Get Started.”

  1. Enter for your zip code, number of people in your household, and the square footage of your home.
  1. Next, indicate what type of energy sources are currently used in your home.
  1. Select “I do not have Green Button data” so that you can enter your numbers in manually.  Gather 12-months’ worth of energy bills, using your actual statements from the electric and gas companies.  If you do not have these handy, you can often access them online.  Enter the start and end dates – month and year – you want to use.
  1. On the next screens, enter the amount of energy  used each month, not the dollar amount of your bill. For electricity, enter the number of kilowatts (kW); for natural gas, enter the amount of  therms.
  1. Now click “Calculate My Score.”


A score of 5 is average, but higher is better.  Keep in mind, these calculations do not take into consideration if you have a pool or other special energy usage situations. Check below your energy use graph for useful tips they provide. For example:

  1. If your energy use is especially high in the winter and summer months, you may benefit by increasing your home’s insulation (especially in the attic), updating the heating system, duct sealing, and installing a programmable thermostat.
  1. If your base energy use is high, you might benefit from purchasing ENERGY STAR certified appliances and electronics, or modifying your behavior related to home energy use (such as altering your thermostat settings, length of showers, etc.).
  1. Revisit the Home Energy Yardstick each month to see the impact of any energy improvements you make to your home and save your progress.
  1. Take advantage of the Home Energy Advisor online. It has lots of great ideas, tips, and offers.
  1. Thinking of buying an existing home? Ask the current homeowner for the last 12-months of energy bills and check to see if you’ll be buying an energy-efficient house, or one that is an energy hog.

If you live in the Nashville area and have questions about anything heating or cooling related, call on Interstate AC Service at 615-832-8500. We’ll help keep your home running efficiently… and maybe get that Yardstick score up!

Posted on 06/15/2019 6:48 AM by Tony Anderson
Wednesday, 15 May 2019

Ever wonder what goes on during a spring maintenance HVAC check?  We follow along while one homeowner, Bob, has his two systems checked out by Lance Waterbarger, technician for Interstate AC Service.   Bob has one system for downstairs – a traditional central air conditioner and gas furnace – and another unit for upstairs – a small dual-purpose heat pump.  Both systems were fairly new, so Bob was happy to pass his maintenance check with flying colors!



Want to have a hassle-free air-conditioning season?  Get a system check-up today.  Call Interstate AC Service at (615) 832-8500.




Posted on 05/15/2019 7:18 AM by Tony Anderson
Wednesday, 17 April 2019

One of our employees, Jeff Parks, along with a group we belong to, BOMA, (Building Owners and Managers Association) has become involved with a charity formed by two women. They needed a van so they could deliver food and supplies to the homeless in both Nashville and Lebanon.  We decided we could fix one of our vans and donate it to this charity   Channel 2 (WKRN) did an interview with Heather Young, the Founder of All For Him Ministry and volunteer Keisha Payton. We were very inspired to see this video. It is a great feeling for all of us to help the homeless in such a basic way.  Thanks, Jeff, for making this happen.


Posted on 04/17/2019 4:57 PM by Bob Duthie
Monday, 15 April 2019

podcast, listenDo you think getting a yearly maintenance check on your HVAC system is a good idea?

Whether you answered “yes” or “no,” you’re only half right! 

If you get just one visit per year, it depends on the time of year you get the visit.  Generally the technician will only test the system pertinent to the season you’re in.  If it’s spring or summer, they’ll check the air-conditioning system.  If it’s fall or winter, they’ll check the heating system.  Why can’t they do both at the same time?  If you had you air-conditioner checked in say, November, and it was fine then, a lot can happen by the time April or May rolls around and your money will not have been well-spent.

We always recommend having two maintenance checks each year: once for the cooling system in the spring and another for the heating system in the fall.  Have the systems checked before you turn it on for the first time that season or at least early in the season.  That’s when you can prevent the most problems from occurring later on.

Here are some benefits to regular, twice yearly maintenance:

  • Better air quality, with less dust accumulation, thus creating a healthier environment.
  • Prolongs the life of your equipment, thus saving you money.
  • Addresses potential safety issues, thus preventing a disaster.
  • Keeps your system more efficient, thus reducing energy consumption and cost.
  • Addresses worn parts and potential problems pro-actively, before a breakdown, thus preventing inconveniences for you.

As a bonus, if you sign up for a maintenance contract with us, you’ll get twice yearly service and a discount on any parts that may be needed throughout the year!  That saves you even more money!  When you think about it, getting an Interstate AC Service maintenance contract can be a pretty smart move!  Call on us at (615) 832-8500 today.

Posted on 04/15/2019 7:19 AM by Tony Anderson
Monday, 01 April 2019

Getting ready for spring often means planting and sprucing up the yard, but it also means getting ready for air conditioning season.  When it comes to spring HVAC maintenance, there are some things you can do and some you’ll probably want to leave to the professionals.

Here are the things you can (and should!) do:

Change the air filters, and make sure the vents are not blocked.air filter



Clean the area around the outside unit. Trim overgrown grass, bushes or trees, to give the unit at least 3 feet of clearance on all sides.



With a garden hose, rinse the outside unit, cleaning dirt that built-up over the winter on the fan blades and fins. For detailed instructions, and precautions regarding coil cleaning products, see our video “The Low-Down on Coil Cleaning.”



With all the rain Nashville has gotten lately, you’ll want to make sure the ground and concrete pad the unit is sitting on hasn’t shifted, and that it is level. Check our video “How Rain & Flooding Affects Your HVAC System” for more.



Blow out the condensate drain and clean the pan.  For step-by-step instructions, see our video “Clean Condensate Lines to Prevent Mold.”



Verify your thermostat is set correctly. Set the date and time, set programming functions for summer operation, and be sure to switch the mode to “Cool” and the fan to “Auto.”


Reverse the settings on any ceiling fans so that the blades are whisking the air upwards. Check out our video post “Are you a ‘Fan’ of Changing Seasons?


Check basements and crawlspaces to ensure they are not trapping moisture which can feed extra humidity into your air ducts.  Nashville’s summers are humid enough!



Some of the most vital spring maintenance tasks will need to be performed by a licensed HVAC technician.  These include:

  • Measuring the refrigerant level, adding refrigerant if needed, and checking for refrigerant leaks.
  • Inspecting all the electrical connections, motors, and safety controls.
  • Lubricating all the moving parts, especially the fan motor.
  • Inspecting and replacing belts as needed.
  • Checking the supply and return temperatures.
  • Cleaning the condenser coils and the condensate drain.

Never forget, the purpose of doing spring maintenance is to avoid breakdowns and expensive repairs, to keep your system running at peak efficiency, and to prolong its life!  The time and effort you put into it now, including having an HVAC spring maintenance check, will pay off down the road.

If you live in the Nashville area and need a maintenance check, call on Interstate AC Service, at 615-832-8500.

Posted on 04/01/2019 7:46 AM by Tony Anderson
Sunday, 17 March 2019

Heavy rains in Middle Tennessee serve as a reminder of the dangers posed by excessive water.  Flooding of roadways and fallen trees come to mind, but have you considered how excessive rain can affect your heating and air conditioning system? The typical central heating & air-conditioning system has 3 main components:

  • an outdoor part - which sits beside or behind your home,
  • an indoor part - usually in a basement, attic, or utility room, and
  • ductwork - which runs all around various spaces inside your home.

Let’s look at how heavy rains can affect each of these.




The outdoor parts – the compressor and condenser coil – are built to withstand all kinds of weather.  The sensitive electrical components are sealed and the connections are insulated and made impervious to moisture. The outer-facing parts are comprised of aluminum, copper, and other metals, which are made to handle heavy rains.  But too much rain can impact the outdoor unit in the following ways:

  • Erosion, gullies, and mudslicks can cause the pad the outdoor unit is sitting on to shift as the heavy rain washes away the earth beneath and beside it. The result is that the unit is no longer level, or in extreme cases, the unit has washed partly or completely off the pad. If you encounter either of these situations, turn the unit off and do not operate it until the unit is made level again, on a firm footing.
  • Debris from the yard or blowing in the wind can wash up near the unit or become lodged in the unit. Branches, leaves, and other debris can fall inside the unit (where the fan blades are), or can damage the fins on the sides of the unit. After a storm, always check the outdoor unit. If the fins have been damaged or you see gashes or holes, turn the unit off and call a professional. Operating the system with debris in or against the unit will cause damage to the unit!  
  • Standing water or flooding around the outdoor unit can be quite serious, as it may have damaged the internal components. Turn the unit off and have it professionally inspected before you restart it. In the meantime, check the source of the water: do you have a broken or blocked gutter or a downspout that needs to be re-directed? If the source of the standing water is due to the unit being located in a low spot in yard, or in an area with poor drainage due to vegetation or slopes, consider relocating the unit or raising it up several feet to prevent future flooding.  
  • Tip: Never use a tarp or plastic bag to cover the outdoor unit. It traps moisture inside, leading to rust, mold, and mildew, which weakens the components and will cause them to break down sooner. It also creates an attractive nesting ground for insects and vermin. Covering the outdoor unit while running the air-conditioner will damage the compressor.


The indoor part – typically the furnace, heat exchanger, evaporator, and air handler – is usually located in a basement, attic, or utility room. Because it is designed to be indoors, its electrical components and construction are not built to withstand rain or extreme moisture. In a heavy rain, or even during a water heater mishap, your basement or utility room may experience flooding. If your unit is located in the attic, be mindful that a roof leak as a result of the heavy rain could develop. Any time your indoor unit is wet or encounters standing water, a short in the electrical circuits can damage the wiring, motors, and electronics, and make the system hazardous. The system should be turned off from the main circuit breaker (not just at thermostat). Do not attempt to start it again without having it thoroughly inspected by an HVAC technician.  


Ductwork, which is often run in crawlspaces and attics, can be impacted by heavy rains. If your crawlspace floods or your roof leaks, the ductwork will get wet. Ductwork is typically not waterproof. Water entering the ducts may remain inside the duct long after the flood itself has receded, and will cause the ductwork to deteriorate. Mold and mildew will begin growing inside your ductwork, giving your whole house a musty smell, and could lead to the perfect environment for toxic mold growth. Roof leaks can often go unnoticed in the attic for some time, and moisture or even standing water in a crawlspace can go unnoticed if it doesn’t raise to the level of impacting the floors. This ongoing moisture will saturate the insulation around the ducts, in the attic, and under the floor joists. Wet insulation no longer does its job, and the increased heat transfer causes your heat and air conditioner to run longer cycles to compensate, or forces you to continually adjust the thermostat to compensate for the reduced efficiency.  But the biggest danger to you and your family from wet ductwork is the reduced air quality and health hazards of mold.

If you are concerned that your system is not working properly due to recent storms in the area, give Interstate AC Service a call at (615) 832-8500. We’ll determine if your system is safe to operate or is in need of repairs.

Posted on 03/17/2019 6:08 AM by Tony Anderson
Friday, 15 February 2019

It’s cold and your heat doesn’t seem to be working!  Did you know your thermostat could be the cause?  Here are some troubleshooting tips and fixes you may be able to do yourself, to save time and money.



  • Power:  Is the display on your thermostat blank? It could be there is no power to the thermostat.  A tripped circuit breaker or fuse could be the problem, possibly caused by a power outage, power surge, lightning strike, or storm. Reset the tripped circuit breaker or replace the fuse. Make sure all the wires going to the thermostat are connected and not loose.
  • Batteries: If your thermostat is battery-powered, or relies on battery for backup power in case of a power outage, it could be that the battery needs replacing.  If you have a programmable thermostat, and had a recent power outage, it could be that without a functioning battery backup, all of your settings have been wiped out by the power outage and the thermostat reverted to its default program. You’ll need to insert a new battery, then re-enter your settings.   
  • Date/Time: Check that the thermostat is set to the correct day and time, including the AM or PM designation.  One customer bought a programmable thermostat to save money, with the intent to have the heat backed down while the customer was away at work, and have the heat cranked up at night when the customer was home.  But when the customer started freezing at night, they mistakenly thought something was wrong with their heat, when the real culprit was they had the AM/PM designation backwards on their thermostat!

Here’s a tip:If you’ve lost your owner’s manual for your thermostat, most major-brand manuals can be found on the web — just go to the manufacturer's web site.

  • Mode: Check that the thermostat is in heat mode. This switch can easily get accidentally bumped into the off or cool position. If it’s a programmable thermostat, switch it to manual control and set it for 5 degrees above the room temperature, and wait to see if the heat cycles on.  If it does not, then the problem may be at the furnace.

If none of these DIY fixes addresses your problem, and you live in the Nashville area, give us a call at 615-832-8500.  We’re here to help!


Posted on 02/15/2019 6:18 AM by Tony Anderson
Tuesday, 15 January 2019

Audio, podcast, listenSingle-Speed Blowers

Variable-speed BlowerIf your furnace or heat pump is more than 10 years old, it likely has a single-speed air handler (blower).  Single-speed blowers work like a light switch: they’re either on (blowing at maximum speed) or off (not blowing).  Single-speed units have been the standard, most affordable option, but they have some disadvantages. 

Disadvantages of Single-Speed Blowers

  • It uses more electricity.
  • It causes large swings in temperature: from too cold to too hot. And because the air does not circulate at all when the blower switches off, the heated air rises to the ceiling.  This is why we recommend running ceiling fans on low, even in the winter.Temperature swing comparison
  • When the blower comes on, you hear a loud rush of air and it can be noisy.  Plus, the surge of electricity it consumes may cause your lights to dim for a second each time it kicks on.
  • Because there are periods when the blower is not blowing at all, humidity control suffers.  In the summer, the air only moves through the de-humidifier when the blower is on (actively blowing), and humidity builds up when the blower cycles off.
  • The constant cycling on and off makes for more wear-and-tear on all the components, and could cause the system to breakdown sooner.

Variable-Speed Blowers

Over the last 10 years, technology has continued to advance, making variable-speed motors less complex, more reliable, more responsive, and more commonplace on HVAC units.  A variable-speed blower runs at different speeds to precisely control the flow of heated or cooled air throughout your home.

AFUE, Energy GuideOn a mild day, the blower runs slower.  The AC or heat runs in longer cycles so the indoor temperature does not spike up and down, thus making overall efficiency higher.  Variable-speed blowers offer the highest efficiency and performance.  The AFUE (annual fuel utilization efficiency) of a furnace with a variable-speed blower may be as high as 95%.

Advantages of Variable-Speed Blowers

  • Sensitivity: Since it operates at different speeds, it can adapt to the unique airflow requirements of a home at any given point in time.  For example, it can compensate for the amount of dirt in the air filter or blocked vents by increasing the fan speed.
  • Energy efficientEfficiency: It always operates at the lowest speed required, thus it saves electricity, and is less costly to operate. This increases efficiency and allows the unit to use about two-thirds less electricity. This results in a 40% year-round energy savings (about 75% of that savings is in heating). 
  • Quieter: Whether running AC or heat, the unit is quieter because most of the time it is not operating at full speed. Plus, it gradually ramps up to full-speed when needed, eliminating the sudden noisy blast of air common with single-speed units.
  • Comfort:  A variable-speed unit will keep you more comfortable because it keeps the temperatures more constant – eliminating the wide swings of too cold and too hot which results from single-speed systems cycling on and off.
  • Air Circulation:  It circulates air continuously, with fewer “off” cycles, allowing more air mixing and preventing the trapping of hot air near the ceiling.  In the summer, it allows the air-conditioner to remove more moisture from the air, decreasing humidity to make you feel more comfortable.
  • Air Quality: Because your air filter is only filtering particles when the air is moving through it, having a variable-speed blower means more air will be filtered.  This means leaving fewer particles to be deposited in your living space, which may translate into fewer allergens and less dust.
  • Longer Life: Since a variable-speed blower is not having to constantly cycle on and off, there is less wear-and-tear and thus fewer breakdowns and a longer operating life for the system.
  • ROI, PaybackPayback: Although the tax credits have expired for buying a high-efficiency variable speed HVAC unit, it is still a wise purchase.  This is because the reduced costs (less electricity consumed, fewer breakdowns) during operation mean you’ll get a return on investment (ROI) in just 4-5 years.

Does it Really Matter?

Bob, a homeowner who recently had a variable-speed HVAC system installed, says “There is a big difference… it does a better job of keeping warm and even throughout the room.”  His old system was quite noisy, so that has been a big improvement, too.  One feature Bob likes about his furnace now is that “it waits until the furnace is warm before it starts to blow hard.”

What System is Right for You?

QuestionsIf you live in the Nashville TN area and need help deciding between the various types of systems on the market and determining which one is best for your needs, give us a call at (615) 832-8500.


Posted on 01/15/2019 7:00 AM by Tony Anderson
Sunday, 16 December 2018

This is a story of a homeowner whose heating and air conditioning reached the end of its life. For most systems, end-of-life can be anywhere from 12-16 years, but with some intermediate repairs, this system’s life was extended to 21 years.   In the fall of 2018, when the homeowners came home from a long trip, there was no air conditioning on the first floor of the house.  Interstate AC Service came out and added refrigerant to the system which appeared to solve the problem.  However, a week later, the refrigerant had leaked out and it became clear that something more would need to be done.  Interstate AC’s  system expert, Tommy Gentry,  discussed options with the homeowners.  


The electric blower controls had been replaced two times in the last 10 years.  The existing HVAC unit was sitting on the basement floor, which made it subject to flooding.  So, the unit needed to be raised off the floor.  There were two rather small air ducts coming from the return and these needed to be enlarged.  Tommy took a lot of measurements and determined that a new 3-ton American Standard would fit the existing space and result in lower costs.  The existing heat pump was eliminated. Tommy drew up a reasonable estimate and the homeowner decided to proceed with the replacement.  Tommy provided drawings for the installers and made a list of parts that would be required. Three days later the truck arrived, and work with a two-man crew began.

  1. First, the gas was turned off, then the refrigerant was drained from the existing unit so it could be recycled.   Next, the exhaust was disconnected from the existing unit, and the old unit was removed and recycled.  Then, the area was made ready for the new furnace.
  2. A platform to go under the unit was put in place, then the blower, coils, and furnace were brought in and were put together.  Lines from the outside unit were brought inside and attached to the new unit.
  3. After a short break, Tommy brought in a load of parts, inspected the job, and helped to rebuild the new unit’s furnace exhaust.
  4. Next, they tackled the outdoor unit.  They cut the wiring and copper pipes to free the old unit so it could be removed and taken to the recycler.  The pad was prepared, and the new unit was unpacked and put into position.
  5. Wiring and copper pipes were now fitted to the new outdoor unit.  Air was evacuated from the pipes and the coils and the new unit was filled with the new, more eco-friendly, 410A refrigerant.
  6. The entire unit  - both heating and cooling – was tested.   Finally, the unit was buttoned up and connected to a new condensate pump.

The homeowner was impressed with the quality of the work and the care that Interstate AC Service took at each step of the way.  The new unit has a variable speed blower motor which makes a huge difference in reducing the noise coming from the unit.  We now have another very happy homeowner.

If you’re pondering a system replacement, let the folks at Interstate AC Service help!  If you live in the Nashville and surrounding area, give us a call at 615-832-8500.  We’re here for you!






Posted on 12/16/2018 2:44 AM by Tony Anderson
Thursday, 15 November 2018


This is part 3 of our 3-part series on alternatives to zoning. Zoning refers to creating separate thermostatically-controlled areas within your home.  But, before doing an expensive retro fit or buying a new multi-zoned system, try some of these things to address and possibly alleviate uneven temperatures in your home.  In this episode, we’ll focus on how Balancing Airflow and employing Spot Treatments may help.



Balancing the Airflow

Some rooms may be hard to heat and cool because of inadequate supply ducts or air register grills.  You may need to increase the size of the supply duct or add an additional duct to provide the needed airflow to the room. Any rooms with a lack of sufficient return airflow may benefit from relatively simple upgrades, such as: installing new or larger return-air registers, undercutting doors for increasing return air flow, or installing a jumper duct to create an air flow connection between rooms.  To see which of these solutions is best for your problem, contact an HVAC professional.

Manual Balancing

You might be able to “manually” balance the air flow by adjusting the dampers in the duct work. For example, in the summer time, you might try partially closing the dampers in the ducts going to the first floor and fully opening the ones to the second floor. This often takes a few tries to get them set right. If you have separate HVAC units feeding each floor, try setting the thermostat for the upstairs about 2-3 degrees cooler than the downstairs in the summer.  This is because heat rises.  In the winter, set the downstairs thermostat 2-3 degrees warmer than the upstairs. 

Spot Treatments

Consider installing a ductless mini-split system in the rooms which are always too hot in summer and too cold in winter.  As the name implies, they do not require ductwork, so they’re easy to install and they’re super-efficient.  This will effectively make the rooms that are fed by the mini-split system their own zones, allowing you to control their temperature independently of the rest of the house.  Check out our many previous posts on mini-split systems. 


Let the folks at Interstate AC Service help you sort out all the options and find the best solution for addressing your uneven heating and cooling problems. If you live in the Nashville and surrounding area, give us a call at 615-832-8500.  We’re here for all your heating and cooling needs. 

Posted on 11/15/2018 7:05 AM by Tony Anderson
Wednesday, 31 October 2018


This is part 2 of our 3-part series on alternatives to Zoning. Zoning refers to creating separate thermostatically-controlled areas within your home to help even out the hot and cold spots.  But, before doing an expensive retro fit or buying a new multi-zoned system, try some of these things to address and possibly alleviate uneven temperatures in your home!  In this episode, we’ll focus on how Reflecting and Radiating Heat may help… and best thing is these are do-it-yourself-type projects!

Insulate the Attic

Beefing up the insulation in the attic – not just around the ducts but all around the floor of the attic - is the one thing you can do that will help the most with both heating and cooling. Plus, you’ll save money on your overall heating and cooling costs year-round.

Insulate Garage

Adding insulation to your garage, particularly to the garage doors, will prevent heat from outside radiating inside in summer, and will prevent heat loss in winter.  Not only will it make your garage a more comfortable space, but it will help your HVAC work a little less hard to keep the adjoining rooms at your desired temperature.

Reflecting Heat

Do you have windows in your garage door or attic?  What about in that one room that always seems to be too hot in the summer and too cool in the winter?  Try Iining the insides of the windows with a UV-reflective window film, which can block 99% of the sun’s UV rays while also reducing heat loss in winter by 30%.  Many types and colors are available, and some are transparent and easily removable.

Radiant Barriers

Consider adding a radiant barrier in the attic to reflect some heat away. A radiant barrier is a highly reflective material that reflects heat rather than absorbing it.  Attics with R-19 or better insulation and a radiant barrier – such as foil-laminated OSB panels or thin sheets of aluminum - may reduce an attic’s temperature by up to 30°F.

A cooler attic or garage means less heat moving into your living space!  This increases the efficiency of your ductwork, prolongs the life of your HVAC, and saves on your energy bills.

While we can’t help you with many of these DIY projects, we can help make sure your heating and cooling units are maintained in top shape for peak efficiency, and help you find the best solution for addressing your uneven heating and cooling problems. If you live in the Nashville or surrounding area, call on Interstate AC Service at 615-832-8500. We’re here for all your heating and cooling needs.

Posted on 10/31/2018 4:26 PM by Tony Anderson
Monday, 15 October 2018


In a previous post, we talked about zoning: creating separate thermostatically-controlled areas within your home to help even out the hot and cold spots.  Although zoning can save you up to 30% in energy costs, it is not without cost itself. Suppose you don’t want the expense of replacing your current system with a new multi-zoned HVAC unit, or re-working your current ductwork layout to accommodate a retrofit. Never fear! There are lots of things you can do to address and possibly alleviate the uneven temperatures in your home. In this post (the first of a 3-part series), we'll focus on how sealing and insulating ducts may help.



Step 1: Seal the ducts

Ductwork is used to distribute the heated or cooled air throughout your home.  In a typical home, 20-30% of the air in the ductwork is lost due to leaks, holes, and poor insulation.  The result is difficulty keeping the house comfortable no matter how the thermostat is set.  Check the ducts in your attic, crawl space, and basement, and look for holes or gaps, areas where the ductwork has been crushed or kinked, or has become disconnected.  Repair and seal the holes using mastic sealant or metal-backed (foil) tape – NOT the typical grey fabric duct tape! Contrary to its name, “duct tape” is not the best solution for sealing ducts.  Cloth-backed utility tapes are not recommended because they will fall off easily, degrade with extreme heating and cooling, and do not reflect heat.  Look for aluminum-backed tape with the Underwriters Laboratories (UL) logo. Duct mastic is the preferred material for sealing ductwork seams and joints, especially irregular or jagged edges.

Step 2: Seal Registers & Vents

Check all the air register vents in each room, and the return air grill, to ensure there is a tight seal between the duct opening and the grill, that there are no tears in the ductwork from debris falling inside the register, and that the duct has not torn away from the opening.

Step 3: Insulate the ducts

Insulate the ducts, especially in the attic where the temperatures soar in the summer, and in the crawl space and basement where the temperatures are coldest in the winter.  Wrap all ducts with foil-faced fiberglass insulation having an R-6 value or greater and seal the joints with foil-faced duct tape.

Prefer a hands-off approach to your ductwork?  If you live in the Nashville and surrounding area, call on Interstate AC Service at 615-832-8500 to help with ductwork repair, or whatever heating and cooling issues you may have.  We’re here for you!

Posted on 10/15/2018 7:41 AM by Tony Anderson
Wednesday, 03 October 2018

One thing I’ve noticed living in Middle Tennessee is that our springs and falls seem to be getting shorter. It seems every year we go right from air-conditioning weather into heating weather (and vice versa!) in the blink of an eye. It is easy to become complacent and “forget” to have your HVAC system’s regular maintenance until it’s too late. After all, when it’s still in the 80’s and 90% humidity, you’re not thinking about how your heat will perform!  But here’s why you should resist that urge, and get your regular HVAC maintenance now:

  1. Prevention: When the cold weather hits, and you find you have a heating problem, you may be waiting longer for service… and have to endure more cold temps…because that’s when everyone else’s system is acting up, too. Get a jump on it now, before the cold hits, and prevent outages – and inconveniences later!
  1. Safety: If a light bulb is going to go out, it will often do so just as you turn it on. Your heat might be the same, and you could have a situation that is preventable. Damaged, broken or poorly vented heating equipment can lead to carbon monoxide poisoning or other safety hazards. Find out now before you first turn on your heat for the season!
  1. Value: Financial analysts and home professionals agree, getting your HVAC inspected at least annually is among the best values for the money. Not only will you be able to head-off large repair bills down the road, but your system will run more efficiently, saving you money every single day it’s in use!  According to Fox News Network, it’s not only about safety, but catching a problem before it happens, because if your heat goes out on a Sunday evening, you’ll wind up paying more in emergency/after-hours rates. Angie’s List encourages you to think of your HVAC unit as an investment that you want to last as long as it can… the real value comes from not having to replace your HVAC system prematurely due to lack of proper maintenance.
  1. Warranty: The warranty on your heating and cooling system often contains language saying that unless it is serviced by a qualified professional, you could void the warranty.


Want to know what’s involved in a fall maintenance check?  Check out our video and our Fall Maintenance Handbook (free download).

Call on Interstate AC Service (615) 832-8500 to schedule your fall inspection today. When the cold finally sets it… and you know it eventually will… you’ll be so glad you did!

Posted on 10/03/2018 1:00 PM by Tony Anderson
Wednesday, 26 September 2018

During the summer, your air conditioner (AC) works harder and longer.  That high demand may cause a problem to rear its ugly head.  In this multi-part post, we’ll take a look at some of the most common AC problems, talk about the possible causes, and provide suggestions for tackling each problem.

Inadequate Cooling


If your system is working fine (no leaks or noises, etc.), but it is not able to maintain the desired temperature you set on the thermostat, especially during the hottest part of the day, it could be that your unit is under-sized for your house. Perhaps you added space on to the house since it was built or removed trees near the house that were providing shade. When excessive demand is being made on the unit and it can’t keep up, you may need a larger unit. To delay having to get another system, you can add extra insulation – especially in the attic – and get double or triple paned windows with low E glass, to help improve your system’s performance. Getting regular tune-ups in spring and fall also helps to maintain your system’s efficiency so it will operate at peak performance. Other reasons for inadequate cooling include:

  • A dirty condenser or evaporator coil
  • A blocked condenser
  • Clogged drain lines
  • A lack of system refrigerant

Avoid AC Problems

Summer can be the best time of the year, so don’t let air conditioning problems hinder you from enjoying it.  Be sure to get annual AC maintenance visits, so it will run efficiently and be ready for the high demand of the summer’s heat.  If you live in the Nashville area and experience any heating or cooling problems, call on Interstate AC Service at (615) 832-8500. 

Posted on 09/26/2018 7:39 AM by Tony Anderson
Wednesday, 19 September 2018

During the summer, your air conditioner (AC) works harder and longer.  That high demand may cause a problem to rear its ugly head.  In this multi-part post, we’ll take a look at some of the most common AC problems, talk about the possible causes, and provide suggestions for tackling each problem.

AC Doesn't Cycle On


If your AC does not cycle on, check to make sure it has power, that the circuit breaker has not been tripped, and that the thermostat is on and set to cool mode. If these check out, then here are some possible causes:

  1. System has frozen up: You might see ice on the inside or outside unit. This is typically a sign that there is a refrigerant leak (described above), but it could also be a sign that the ductwork is blocked or a dirty air filter. Turn the system off, turn the thermostat to fan, and wait for the ice to defrost, which may take several hours. Meanwhile, call an AC professional.
  2. Condensation (drip) pan is full: When condensate drips from the evaporator into the drip pan, the excess water should be carried away via pipes to the outside. If these pipes – the condensate lines – get clogged, a water float switch will automatically turn the AC unit off. If your unit is not equipped with a float switch, you will instead see water leaking from the around the drip pan. Dry out the drip pan and clean the condensate line. Refer to our post Clean Condensate Lines to Prevent Mold).

Avoid AC Problems

Summer can be the best time of the year, so don’t let air conditioning problems hinder you from enjoying it.  Be sure to get annual AC maintenance visits, so it will run efficiently and be ready for the high demand of the summer’s heat.  If you live in the Nashville area and experience any heating or cooling problems, call on Interstate AC Service at (615) 832-8500. 

Posted on 09/19/2018 7:27 AM by Tony Anderson
Wednesday, 12 September 2018

During the summer, your air conditioner (AC) works harder and longer.  That high demand may cause a problem to rear its ugly head.  In this multi-part post, we’ll take a look at some of the most common AC problems, talk about the possible causes, and provide suggestions for tackling each problem.

AC is Blowing Hot Air



If your AC is not cooling or is blowing hot air, here are some possible causes and solutions:

  1. Thermostat turned to heat mode: Switch it back to “cool” and you’re good to go.
  1. Dirty evaporator coil caused by a dirty air filter:  Change air filters.  You may also need to have the evaporator coil (inside the indoor part of the AC unit) professionally cleaned.
  1. Condenser coil obstructions: Check the outside AC unit for anything blocking the condenser’s air flow, and clean any debris (such as grass clippings, overgrown bushes, etc.) around the unit.
  1. Low on refrigerant/Freon:  This is usually caused by a refrigerant leak somewhere in the system and looks like ice forming on either the inside or outside unit or both.  For this, you’ll need to contact an AC professional.  See our post Adding Freon to your AC is NOT a DIY Project.

Avoid AC Problems

Summer can be the best time of the year, so don’t let air conditioning problems hinder you from enjoying it.  Be sure to get annual AC maintenance visits, so it will run efficiently and be ready for the high demand of the summer’s heat.  If you live in the Nashville area and experience any heating or cooling problems, call on Interstate AC Service at (615) 832-8500.


Posted on 09/12/2018 7:18 AM by Tony Anderson
Wednesday, 05 September 2018

During the summer, your air conditioner (AC) works harder and longer.  That high demand may cause a problem to rear its ugly head.  In this multi-part post, we’ll take a look at some of the most common AC problems, talk about the possible causes, and provide suggestions for tackling each problem.

AC Runs Continuously


Perhaps the AC is cooling but you notice it’s working harder and longer.  You might also notice a sharp increase in your energy bills compared to last year at the same time.  This may be due to a sensor problem, which is causing improper monitoring of the temperature of the evaporator coil.  Typical sensor problems include: the sensor isn’t positioned in the right place, the connections to and from the sensor have failed (due to an electrical short, for example), or the sensor itself has died.  A professional AC technician will be needed to investigate and remedy these situations.

Avoid AC Problems

Summer can be the best time of the year, so don’t let air conditioning problems hinder you from enjoying it.  Be sure to get annual AC maintenance visits, so it will run efficiently and be ready for the high demand of the summer’s heat.  If you live in the Nashville area and experience any heating or cooling problems, call on Interstate AC Service at (615) 832-8500. 

Posted on 09/05/2018 7:58 AM by Tony Anderson
Wednesday, 29 August 2018

During the summer, your air conditioner (AC) works harder and longer.  That high demand may cause a problem to rear its ugly head.  In this multi-part post, we’ll take a look at some of the most common AC problems, talk about the possible causes, and provide suggestions for tackling each problem.

Unit Shuts Off Repeatedly


If the unit is turning on and off repeatedly, or has difficulty switching on, or you hear a choking and stuttering sound while turning it on, there is short cycling problem.  This can severely damage the compressor, stress the other components, and will consume excess electricity.  Some possible causes are an electrical short somewhere in the system, poor wiring (this is serious and could cause a fire), a damaged or failed part in the system, dirty air filters, or blocked ducts preventing the flow of air.  If you continue to have a short cycling problem after checking your air filter and vents, turn the system off and contact an AC professional.  In some cases – especially if the problem has persisted a while – you may require a new AC unit entirely..

Avoid AC Problems

Summer can be the best time of the year, so don’t let air conditioning problems hinder you from enjoying it.  Be sure to get annual AC maintenance visits, so it will run efficiently and be ready for the high demand of the summer’s heat.  If you live in the Nashville area and experience any heating or cooling problems, call on Interstate AC Service at (615) 832-8500. 

Posted on 08/29/2018 6:07 AM by Tony Anderson
Wednesday, 22 August 2018

During the summer, your air conditioner (AC) works harder and longer.  That high demand may cause a problem to rear its ugly head.  In this multi-part post, we’ll take a look at some of the most common AC problems, talk about the possible causes, and provide suggestions for tackling each problem.



While your AC is running, you should hear the hum of the blower, a click when your air conditioner turns on, and the whir of the outside condenser fan.  Other noises – such as rattling, screeching, thumping, clanging, or banging - mean your system is having problems.  Typical causes of noise from the AC unit include: a belt wearing out, loose hardware, a failing motor, refrigerant issues, or blower issues.  But try these things first: make sure the filter is clean, that the air vents in all rooms are unblocked, and that there are no obstructions around or in the outside unit.  If you still hear strange noises, contact a professional AC service technician before the situation worsens and leads to big repair bills and prolonged downtime.

Avoid AC Problems

Summer can be the best time of the year, so don’t let air conditioning problems hinder you from enjoying it.  Be sure to get annual AC maintenance visits, so it will run efficiently and be ready for the high demand of the summer’s heat.  If you live in the Nashville area and experience any heating or cooling problems, call on Interstate AC Service at (615) 832-8500. 

Posted on 08/22/2018 6:57 AM by Tony Anderson
Wednesday, 15 August 2018

During the summer, your air conditioner (AC) works harder and longer.  That high demand may cause a problem to rear its ugly head.  In this multi-part post, we’ll take a look at some of the most common AC problems, talk about the possible causes, and provide suggestions for tackling each problem.

External Fan (Compressor) Not Working




Check all around and inside the outdoor unit.  Verify that the fan blades are unimpeded.  It could be that the outdoor unit sustained damage due to falling debris from storms.  Be sure to keep the area around the outdoor unit clear of debris and check it often throughout the summer and fall.  If there are no obstructions and the fan blades are not turning, it could be caused by a lack of power to the system.  Cycle the power by turning the circuit breaker off and back on again, then set the thermostat lower than the current inside temperature and wait 2-5 minutes.  If you do not hear the compressor kick in and the fan blades start to turn, you probably have a faulty motor or compressor, and will need to contact a service professional.

Avoid Summer AC Problems

Summer can be the best time of the year, so don’t let air conditioning problems hinder you from enjoying it.  Be sure to get annual AC maintenance visits, so it will run efficiently and be ready for the high demand of the summer’s heat.  If you live in the Nashville area and experience any heating or cooling problems, call on Interstate AC Service at (615) 832-8500. 

Posted on 08/15/2018 5:52 AM by Tony Anderson
Wednesday, 01 August 2018

audio, podcast, moldThe long, humid summers in Middle Tennessee are conducive to mold and mildew and its associated odors forming in your home.  In this post, we’ll help you get to the bottom of any mold issues you may have and alleviate this smelly and potentially hazardous problem.

What is Mold?

Mold is a microscopic fungus that travels as spores in the air and dust all around us – inside and outside.  It thrives in moisture and easily builds colonies.  Mold can cause health problems for you and your family – such as sinus, allergy, and respiratory issues.  Some molds produce deadly mycotoxins – the so-called “toxic molds” or “black mold” – which can cause neurological issues and even death.  Contrary to popular belief, not all black-colored mold is the toxic type, and not all strains of toxic molds are black-colored.  However, anytime you see mold, it bears investigation.

Causes & Prevention

To begin ridding your home of the foul odors and health hazards caused by mold and mildew – and to prevent them from re-occurring - here are some things you can do:

  1. Change air filters.  If you have not been changing your air filter on a regular basis, change it!  Your system’s filter pulls odor-causing contaminants out of the air and if the filter is overloaded, the captured contaminants could be recirculating back into your home when the air conditioner is in use. 
  2. Clean-up the environment.  Since mold spores are most prevalent in dust, be sure to vacuum and clean your surroundings regularly, including changing linens.  Use exhaust fans while showering and cooking to dissipate humidity as needed.
  3. Fix leaks & replace seals.  Make sure there are no active leaks around appliances and plumbing, in the basement, crawl space, and roof. Replace the seals around the tub, shower, or windows where moisture collects. If there was ever a flood where the carpet, flooring, or drywall got wet, don’t just “let it dry” - get it replaced!  This can be a particular problem in Nashville, where so many houses were damaged in the 2010 floods, or experienced a burst pipe or ice damming in the winter which caused interior flooding.
  4. Fix drainage issues. Check for any standing water or drainage issues around the foundation of your home. This may be due to landscaping or erosion issues, or to faulty gutters.  Get the basement waterproofed or install a sump pump, if necessary. See our video Excess Humidity: Causes & Solutions.
  5. Service the HVAC system. During a spring/summer HVAC maintenance visit, the evaporator coil and condensation lines are cleaned. This is crucial, since a condensate drip pan is the perfect environment for mold and algae growth and is the second leading cause of AC failure.  See our video Clean Condensate Drain Lines to Prevent Mold.
  6. Check the ductwork. If you turn off your HVAC system and wait 20 minutes and the mildew smell or foul odor seems to dissipate, and returns when the system is back on, that could be a sign that the problem lies in your ductwork. Moisture and odors can enter the ductwork through a tear, gap, or hole in the duct, and then circulate through your home. In some cases, duct cleaning or replacing the ductwork may be necessary, but if caught early, just re-sealing the duct may do the trick.
  7. Test.  Buy a home mold testing kit – easily obtainable at local hardware and home supply stores for under $10. Get at least one test kit per floor, and a separate one for the basement.  After setting up the kit in the house for the required length of time (usually a few days), mail it off to a testing lab to find out what types of molds are present and whether there is cause for concern (note: a lab testing fee of about $40 may apply).  If you’re buying a new or pre-owned home, get a professional mold inspection from a reputable company with appropriate certifications.
  8. Removal & remediation.  Mold removal and remediation is a specialty of its own, and not something a homeowner should attempt themselves.  It requires specialized training, equipment, chemicals, and wearing of personal protection devices. Use only companies that are specifically certified and licensed for this type of work.

If you care about the quality of the air you and your family breathes every day – and want to prolong your HVAC investment – call on Interstate AC Service at 615-832-8500.  We’re here to help with all your heating and air-conditioning needs.

Posted on 08/01/2018 6:01 AM by Tony Anderson
Sunday, 15 July 2018

Podcast, audio, listenPerhaps you’re really handy around the house, and enjoy taking on fix-it projects.  Adding refrigerant to your HVAC system – what we call a “shot of Freon” – is definitely NOT a do-it-yourself task!   

Iced Up!

When your air conditioner is low on Freon, it means this colorless gas is leaking out from somewhere in the system (see Causes of Refrigerant Leaks). Typically, you will see ice forming on either the inside or outside unit or both.  If this happens you need to turn the HVAC system off completely, wait for it to thaw out, and call an HVAC professional. 

not DIYNot DIY

Here are just some of the many reasons why you cannot just “add a shot of Freon” to your AC yourself:

  1. EPA 608 CertificationPossessing most refrigerants – which are toxic chemicals - requires a special EPA 608 certification, which typically only licensed HVAC contractors can get.  It is unlawful to possess HVAC refrigerants without such a license.  If you find a seller that will sell directly to a consumer and does not ask for your 608 certification, then you should be suspicious that what they’re selling is counterfeit (see our post Fighting Back Against Fake Refrigerants).
  2. RefrigerantsThere are now many different type of refrigerants on the market and each unit will work with only a certain type.  Putting the wrong type of refrigerant in your unit will damage the unit, and could also cause significant hazard to you!  Furthermore, as one refrigerant (R-22) has been phased out of production, other refrigerants may be used in its place, but may require certain updates to your system in order to do so.  You cannot assume that a supposedly “equivalent” product is compatible with your system.
  3. To replace the leaky part or to update the refrigerant, the “old” refrigerant needs to be evacuated first.  But this cannot be done simply by exhausting it into the air (it is unlawful to do so)!  It must be captured into a special pressurized container so it can be recycled. Keep in mind that refrigerants are gasses at room temperature, and are compressed under extraordinary pressures in order to liquefy. Special gear is required to diagnose where the leak is, and to evacuate the old refrigerant and fill with new refrigerant.  Purchasing the appropriate gauges, diagnostic equipment, and pressurized vessels would exceed the cost of the service call.
  4. penny wise pound foolishDepending on the source and extent of the leak, it may be better and more cost-efficient to replace the entire unit, rather than to continue to fill it with Freon that will only leak out again in a short time. Sure, the cost to repair or replace your system may be higher than simply adding another "shot of Freon," but not addressing the cause of the leak causes recurring expenses that will only escalate.  For example,  recharging the system several times could cause the oil in the compressor to deplete enough to damage the compressor, and then you may require a major, really expensive repair! 

Are You Cost-Conscious?

The bottom line is this: if you’re cost conscious, then the best “bargain” is calling an HVAC professional when your system needs a shot of Freon.

phone call

If you live in the Nashville area, call Interstate AC Service at 615-832-8500.  We'll help you with whatever ails your HVAC system.

Posted on 07/15/2018 7:30 AM by Tony Anderson
Friday, 15 June 2018

Foul odors coming from your cooling system are more than an unwelcome inconvenience – they can be downright dangerous.  Air conditioner smells are most often caused by mold and mildew growing somewhere within the system.  In this post, we’ll look at how your HVAC system can harbor mold and be responsible for circulating musty odors.




Air conditioners work primarily by dehumidifying the air.  The water drawn out of the air drips from the evaporator coils into a condensation pan (or drip pan) under the HVAC air handling unit. Drip pans are the perfect environments for mold and algae growth, which then can clog the drain lines.  If the moisture is unable to flow out of the system, the water backs up and can overflow the drip pan, causing water damage in your home as well as causing your air conditioner to shut off.  In fact, a clogged condensate drain line is the second leading cause of AC failures. 

Regular Maintenance is Essential

As part of regular spring/summer HVAC maintenance, the evaporator coil and condensation lines are cleaned.  Having your system’s evaporator coil cleaned not only works to reduce smell, but the procedure will also improve the efficiency of your air conditioner. The mold, mildew, and dirt deposited on your coil will reduce airflow through the system, lowering its efficiency, and causing your HVAC to fail sooner.

Clean Condensate Pan & Drain Lines

But even if you’ve had your system cleaned at the beginning of the season, the condensate drain line could still become clogged during the course of use.  So, it is important to check the condensate pan and drain lines monthly throughout the air conditioning season.  Here’s how:

  1. Find the condensate pan – usually a metal or hard plastic pan about 3 inches deep – sitting below the HVAC’s air handling unit. In some cases, you may need to remove a metal panel to access it. The condensate pan should be nearly dry.  If it has significant rust all over, or is rusted out in sections, it must be replaced. Plus, signs of rust means there has been water backing up in the pan regularly, which is not a good sign.
  2. If the condensate pan has standing water in it or if there is water on the floor nearby, there is a problem with the condensation drain lines.  If your HVAC unit is in the attic, you might see water coming through the ceiling!  If this is the case, turn the HVAC unit off at the electrical switch and at the thermostat. Using rags or a wet/dry vacuum, remove all the water from the drip pan and around the unit.  Then clean the pan with a mild dish soap or 10% bleach solution.
  3. The drip pan connects to the condensate drain line, which carries water out of the home.  Locate where the drain line exits outside the house.  Be sure there are no obstructions, that the drain line is not buried under dirt or landscaping, and that you can see whether it is dripping.
  4. If no moisture is exiting outdoors even while the system is running or when the condensate pan is full of water, then the drain line is clogged. You may need to use a long, flexible rubber tube through the line – from each end – to dislodge the clog.  Another option is to connect the wet/dry vac to the outlet, and use your hands to make a “seal” around the drain line in order to draw the clog out, or use an AC drain sucker kit.
  5. With the system turned off, flush out the drain using distilled vinegar, hot water with mild dish soap, or a 10% bleach solution. Leave the solution to soak for up to 30 minutes, then rinse the lines with clean water. Be sure you can see the water exiting freely out of the exterior condensate line.
  6. Special cases: If the drain line does not have a direct downward slope allowing it to make use of gravity to help the water exit, you may need to have a small pump added to help push the water out.  If there is a reservoir which holds water until it exits, you may need to add a mild bleach solution, condensate drain line cleaner, or anti-algae tablets to the reservoir on a regular basis to prevent the growth of mold and algae. 

If you care about the quality of the air you and your family breathes every day – and want to prolong your HVAC investment – be sure to get your HVAC serviced regularly, and keep that condensation pan and drain clear! If you’re not comfortable with any of the steps listed above, call on Interstate AC service at (615) 832-8500. Rest assured, we’re here to help!

Posted on 06/15/2018 7:14 AM by Tony Anderson
Tuesday, 15 May 2018

We’ve been in the business almost 20 years now and have installed and serviced a variety of HVAC units. HVAC brands, HVAC manufacturersWe are not paid by manufacturers to promote their brand(s); instead, we recommend brands based on our vast experience and our customer’s individual needs.  If the customer has a preference for a certain brand, we do our best to provide it.  But, if you really want to know which brand is best, here are the facts:

The Dirty Little Secret

When you look beyond the label slapped on the outside of the unit, you’ll see that most of the internal components are the same.  There are about six HVAC equipment manufacturers in the U.S. who make about 150 different brand names.  Many of them use the same internal components and are produced on the same assembly line in the same factory.  Goodman and Amana are made in the same factory, yet Amana typically costs more.  Carrier, Bryant, Payne, Tempstar, and Day and Night are made in the same factory, yet Carrier has more name recognition due to more advertising.  York and Luxaire are both owned by Johnson Controls.  There’s almost no difference between Trane and American Standard.  Lennox, Ducane, and Concord are all made by Lennox.  Even less obvious is that some of the internal components of all brands are made by just a handful of third-party companies, making many components interchangeable between brands.  With so much the same, what’s the real differentiator?

The Real Differentiator

HVAC ContractingUnlike many other products, when you purchase an HVAC system, much of the design and engineering occurs on-site (at your home).  Each home is different and presents different challenges with ductwork, physical location, clearances, etc.  No brand, no matter how much it cost and its reputation, will perform reliably if not installed and maintained correctly.

The overwhelming majority of HVAC failures are the result of improper installation or maintenance.  In fact, a good percentage of our business comes from people who hired the cheapest contractor to install their unit, or who think they saved money by not having regular spring and fall maintenance.  There’s a proper way to install and maintain an HVAC unit and it’s worth paying for that expertise, because going with the lowest bid can often cost you later. 

Just as not all doctors, mechanics, or hair stylists are the same, neither are all HVAC contractors.  Sometimes, it’s worth going a bit out of your way, or waiting an extra day for an appointment to get a professional you trust.

Tips and AdvicePitfalls to Watch For

Watch out for contractors who:

  • will offer you a great deal on a discontinued model,
  • do not provide continuing education for their technicians or use transient laborers,
  • don’t inspect your existing ductwork (if it’s a replacement) or will quote you a price over the phone,
  • won’t be around to honor the service agreement you purchased. Interstate AC Service

At Interstate AC Service, we use only qualified, licensed HVAC service technicians, we never use undocumented workers, we provide continuing education to our technicians, our technicians are not paid on commission, and we are committed to customer service.

Buyer Beware!

Don’t be fooled by a system that says it will last for 20 years.  Not without regular maintenance it won’t!   If you neglect your system, it won’t matter what brand you buy!  Here are some other things to watch for:

  1. Proprietary Design:  With some brands, the parts may be proprietary and not interchangeable.  So, there may be longer wait times for replacement parts because you can only get them from one manufacturer, and it may make the unit more expensive or difficult to maintain over time. 
  2. SEER labelSpecifications:  When comparing units, be sure you’re comparing apples to apples.  Comparing a SEER 14 unit to a SEER 21 unit is not valid, because each is built to different specifications and their cost to operate varies widely.  Be aware that not all manufacturers offer units with the same SEER rating (Don’t know what a SEER is? Check out our post What’s Your SEER?).
  3. Features:  Look at the extras that may be rolled into the price.  Is part of what you’re paying for the extended warranty?  A bigger thermostat screen might not be worth paying extra for, but a quieter unit may be… only YOU can determine what features are of value to YOU.
  4. Reviews:  Few people will go online to write something positive about an air conditioner, heat pump, or furnace.  It’s only when it doesn’t work that people typically feel compelled to write a review.  Keep in mind when reading reviews, you cannot know reliably what the circumstances were.  Most failures are not due to the workmanship inside the unit but to the faulty installation and maintenance.  Did the installer install a mismatched AC condenser and evaporator?  Was the unit maintained under a service contract the entire time?  Take the reviews online with a grain of salt!
  5. Allegiances: Use an impartial contractor – one that is licensed to install and service all major brands.  A “factory-authorized dealer” for a single brand can only offer you the prices and features of that brand, even if that might not be best for your needs.  Not having a vested interest in one particular brand means you’ll have more options. [Note: Interstate AC Service is licensed to install and service all major brands – both residential and commercial.]

Bottom Line

The most important aspect of your HVAC system is not the brand you choose, but the contractor!  Except for minor differences, all brands are fairly comparable, but it’s the installation and service that matters.  Unfortunately, buying a “top” brand (one you’ve heard of or has good reviews) doesn’t matter much when it comes to HVAC units.

If you live in the Nashville or surrounding area, and need help with an HVAC issue at your home or business, know you can call on Interstate AC service at (615) 832-8500.  We’ll provide unbiased, professional service you can trust. We never forget we’re here for you!



Posted on 05/15/2018 6:52 AM by Tony Anderson
Sunday, 15 April 2018

audio, podcast, AC tons, Tons to BTU conversionWhen sizing up a new air conditioner, heat pump, or HVAC unit, it is common to hear the pros throw around terms involving tonnage, saying for example, you need a 3-ton or 4-ton unit.  For reference, 4 tons is about the weight of an adult elephant!  But don’t be alarmed: they’re not talking about the weight of the unit!  This is a throw-back from the 1800’s and the term stuck.  You may also hear pros refer to the capacity of HVAC units in terms of BTUs.  Did you know these terms are related?  Here’s how they originated:

Historical Perspective

ice harvestBefore the modern air conditioner was invented, people used to cool buildings in the summertime using ice harvested from rivers and lakes. Gathering the ice from farther and farther north and shipping it down south, or storing it from winter until summer, meant a lot of ice was lost to melting.  A BTU, which stands for British Thermal Unit, is the amount of heat required to raise 1 pound of liquid water 1 degree.  But, when water is below freezing (less than 32 degrees Fahrenheit), the amount of heat needed to melt ice is 143 BTUs per pound.

How the Math Works Out

cooling, tons to BTUs, AC TonA ton weighs 2,000 pounds, so to melt a ton of ice it takes (143 BTU/lb) x (2,000 lbs) = 286,000 BTUs.  How quickly the ice will melt depends on how quickly you heat it.  If you apply the heat uniformly over a 24 hour period, the ice will have absorbed (286,00 BTU) / (24 hours) = 11,917 BTUs per hour.  That number is generally rounded up to 12,000 BTU/hr.  So, a one ton air conditioning unit has the capacity to cool up to 12,000 BTU/hr.

Sizing an AC Unit for Your Home

When comparing costs of different HVAC units, be sure you are comparing similarly-sized units.  Central air conditioning units frequently have the capacity coded into the model number: for example, model RDR36 would be a 36,000 BTU unit, or expressed in tonnage – with 12,000 BTUs being the heat needed to melt 1 ton of ice - the model RDR36 would be a 3-ton unit (= 36,000 / 12,000).

Multiple Factors Affect Sizing

sizing HVACIf you have a 2100 sq.ft. home, a 2-ton heat pump will not be adequate; you’ll need maybe a 3.5 or 4 ton unit. Here’s where having a professional who can do a site visit helps. There are many things that contribute to sizing an HVAC system, other than the number of square feet you want to cool.  Here are just a few:

  • How well the house is insulated and when it was built
  • The numbers and sizes of the windows and doors in the house
  • The color of the roof: darker ones absorb more heat
  • The height of the ceilings
  • The overall shape of the home: long narrow houses lose more heat (through walls) than a more square house of the same size.
  • The size of AC’s condenser, and whether it is positioned in the shade or in the sun
  • The efficiency of the cooling unit, often expressed as a SEER rating, or seasonal energy efficiency ratio (see our post What’s Your SEER?).

Moral of the Story

knowledge is PowerKnowing the number of BTUs that will be required to heat and cool your house effectively is not only important in choosing the right size furnace and air conditioning system, but it can also tell you whether your existing system may be too large or too small… yes, a system that is too large will not cool effectively, so bigger is not always better! (read our post Think Bigger is Better?)  Now that you know that tonnage does not refer to the weight of the unit, and how to convert from tons to BTUs, you can more readily compare units. Proving yet again that knowledge is power!


If you live in the Nashville and surrounding area, and need some help figuring out the right BTUs and tons for your home, we’ll be happy to help.  Plus, if you haven’t had your spring tune-up yet, now’s the best time!  Call on us at 615-832-8500. 


Posted on 04/15/2018 8:00 PM by Cheryl Austin
Friday, 16 March 2018

Harnessing solar energy does not mean you need photovoltaic panels on your roof and technological solutions.  There are many ways to design passive solar into a home that will allow you to lower your heating and cooling costs year-round, and make your home more environmentally friendly.

What is Passive Solar?

Podcast, Audio, Passive SolarPassive solar means using the building’s windows, walls, and floors to collect, store and distribute solar energy in the form of heat in the winter, and rejecting solar energy (heat) in the summer.  It is called “passive” because it does not use mechanical means to distribute heat, but rather takes advantage of natural convection, radiation, and air flow.

Is it worth it?

If you’re adding energy-efficient features into an older home (built before 1993) that currently has little insulation, less energy-efficient windows, and non-EnergyStar appliances, you may be able to reduce heating and cooling costs by up to 50-60%.  That savings will pay for itself year after year, and many of the passive solar design features also add aesthetically to the house and increase the house’s market value (see “Going Green Can Add Value to Your Home”).

passive solar design, going green, home improvement, heating and cooling10 Ways To Incoprporate Passive Solar

If you are not building a new home from scratch, you may not be able to take advantage of all of the suggestions below, but, the more you can do, the more you’ll save.

  1. Use wide overhangs on your house to shield the house from the sun in summer. Western or eastern-facing windows are particularly vulnerable to overheating in summer, so these should be shaded using overhangs and large leaf-bearing shade trees that shed their leaves in the fall.
  2. Have south-facing windows that have an unobstructed view of the sun (no big trees or tall buildings in the way).  Keep these windows clean and keep the drapes, blinds, or shutters open during the cooler months while the sun is shining.  In the warmer months, place a removable reflective film on these windows or keep the drapes, blinds or shutters closed to block the sun.  Remember: if light can get in, so can radiant heat.
  3. Capture and store the sun’s heat in thermal masses inside the house.  This can be concrete, brick, stone, or tile which is used on walls or floors.  The thermal mass absorbs heat from sunlight during the heating season, and absorbs heat from the air during cooling season.  You can easily create a thermal mass by having a brick or stone fireplace which extends up the entire wall, or adding tile or decorative concrete flooring in the room containing the best sun exposure.
  4. Take advantage of the “chimney effect” (natural convection). Since heat rises, install operable skylights (skylights that open) in the upper-most areas of the house, such as an upper floor or vaulted ceiling.
  5. Use clerestory and transom windows or light tubes to let natural light in year-round, so you minimize the use of electric lights. Convert all lights in the house to LED bulbs, which radiate far less heat.
  6. An open floor plan takes advantage of passive solar the best, as do open stairwells and atria.
  7. Install EnergyStar-certified appliances and fans throughout the home, and energy-efficient double or triple glazed windows. Casement windows offer the best air flow.
  8. Add insulation to your attic.  This will help year-round (see our post “5 of the Best HVAC Investments You Can Make”).
  9. Make your roof reflective with a light color paint, or by using reflective paint, shingles, or tiles. Roofs receive the majority of solar radiation delivered to a house, so a cool roof will dramatically cut air-conditioning bills.
  10. Allow the landscape design to work in your favor. Use evergreen hedges and shrubs as windbreaks. Use deciduous trees (trees that drop their leaves in fall) near the house, to provide shade in summer and allow light in in winter.

The real joy comes in living in an energy-efficient, eco-friendly, passive solar house that is not only beautiful, but saves you money every single day.


If you live in the Nashville or surrounding area, Interstate AC Service can help with all your heating and cooling needs.  Call on us at 615-832-8500.  We're here for you!

Posted on 03/16/2018 1:00 PM by Cheryl Austin
Thursday, 15 February 2018

Podcast, ListenIt’s no surprise that the demand for air-conditioners is highest in the summer, and the demand for furnaces is highest in the winter.  If you have an old or failing HVAC system, it will likely go out when it is stressed the most - on the coldest or hottest day of the year – when the demand is greatest.  Well, that’s when everyone else is calling for service, too!  So you may find, no matter what HVAC company you call, they won’t be able to get to you right away.  [If you’ve ever had the unfortunate experience of needing a tow truck after slipping on snowy/icy roads, you know what I mean!]   

Be Pro-Active!

Reactive-ProactiveThe best time to get a new furnace is in the spring and summer, and the best time to get a new air-conditioner is in the fall and winter.  Of course, if you’re replacing an entire system – like a heat-pump that is used for both heat and air – then the best time is during the “in-between” seasons – spring and fall – when systems are less stressed and the HVAC companies are not overrun with service calls.

Benefits of Being Pro-Active

Being pro-active has many added benefits:

  1. Broken HVAC, No air-conditioning, HotYou may get off-season discounts or manufacturers’ rebates.  Plus, you’ll have time to get a professional analysis done of your home, get 2 or 3 quotes, and do research on the companies.  You won’t be in a “desperate” situation: like having no air conditioning on a day with 90+ degree temperatures and 90% humidity!
  2. It’s less disruptive for the homeowner.  You can schedule the install at a convenient time for you, and you won’t have to worry about being down (without heat or air) when it’s most needed!  Face it: it’s much less of an “inconvenience” to be without heat or air (while your old system is being removed and your new system is being installed) when it’s not freezing cold or blazing hot out!
  3. It gives you time to research the various kinds of systems, and the various features, to find the one best for you.  When it’s 7 degrees out and you’ve been without heat for 12 hours, you’re not going to be in much of a “shopping” mood and may wind up getting whatever is readily available and can be installed quickly, rather than the best system to meet your needs.

Think Spring!

If you know your HVAC system won’t stand another winter or summer… don’t just let it slip your mind as we approach spring.  That’s when you SHOULD be thinking: now’s the best time to replace it!  Remember, the best time to buy a new system is before your existing system fails, and before the extreme hot or cold weather arrives.

Brands, Lennox, Rheem, Carrier, TraneIf you need heating or air-conditioning service, no matter the season, call on Interstate AC Service at 615-832-8500.  We’re here to provide all of Nashville and surrounding areas with professional , dependable HVAC system service and installation.

Posted on 02/15/2018 5:53 AM by cherylaustin
Sunday, 21 January 2018


One of the common problems we encounter is a heat pump that has iced up.  A heat pump in good condition should be able to operate in below freezing temperatures without icing over, so why does this happen?

Things to Eliminate

Here are some circumstances that cause icing which you may be able check, fix or eliminate: 

  1. Check to make sure the outdoor unit is not blocked by leaves or covered in any way.  Some people mistakenly think that covering the outdoor unit helps protect it from bad weather in the winter, but this is dead wrong. It always needs proper airflow around it.
  2. Check to make sure you do not have water dripping into the unit by a leaking or blocked gutter.  As temperatures drop, that water will harden into ice and could cause the fan blades to cease up.
  3. Check to make sure there is room for water to drain away from the unit… that it hasn’t sunken into the ground.  If water pools around the unit, it will freeze as temperatures fall, and the ice will impede the operation of the unit.
  4. Check to make sure that nothing is restricting airflow inside the house, such as dirty filters or blocked vents.

If you’ve eliminated these as possible sources of the problem, then it could be a mechanical or electrical problem inside the unit itself.  First, let’s look at how a heat pump should work.

How Heat Pumps Work

The refrigerant inside the heat pump transfers heat back and forth as needed. Even in the winter, there is heat that can be extracted from the outside air to help heat the inside of your home.  But to do so, the refrigerant needs to get very cold… much colder than the outside temperature.  When coils get this cold, water vapor in the air will start to crystalize into ice around them. To prevent ice build-up, the heat pump will periodically go into a defrost mode.  A valve switches so that the outdoor evaporator becomes the condenser.  This allows the coils to get warm enough to melt any ice that may have formed.  While in defrost cycle, the fan turns off so you won’t get cold air blowing on you, or a second-stage heater comes on to offset this cold air.  After the outdoor unit reaches a certain temperature, or after a certain amount of time goes by, the valve switches back and the system returns to normal heating mode, reversing the evaporator and condenser. This cycling on and off happens transparently to the user while the heat pump is in use.

Reasons Heat Pumps Ice Up

  1. Perhaps the most common reason heat pumps ice up, is that the reversing valve gets stuck.  This prevents the heat pump from going into its defrost cycle and the ice on the outdoor coils continues to accumulate until it impedes the turning of the fan blades. 
  2. If the reversing valve is fine, it could be that something is wrong with the defrost timer, sensor, or control module, so that the defrost cycle is not completing or not happening often enough or not being triggered at all due to a faulty thermostat or sensor. 
  3. If the system is low on refrigerant or the outdoor fan motor dies, this could also cause the system to ice up.

Each of these reasons will likely necessitate a service call.

In the Meantime…

If you can visually see your outdoor unit has iced over, turn the unit off.  If you are able to, turn on the emergency heat mode until help can arrive.  Do not continue trying to run the unit “normally” as this will only cause more damage, and don’t wait too long before seeking help, as this may increase the extent of repairs that are necessary.  Do not try to pick off the ice with a sharp object, as the coil and fins will damage very easily, and you may cause a refrigerant leak.


As with most HVAC systems, problems with a heat pump can often be prevented with proper maintenance.  Getting a fall maintenance check before the worst of the cold weather sets in, and getting a spring maintenance check before the heat of the summer, will help lessen the probability that you’ll find yourself all iced up!

If your HVAC system needs attention and you live in the Nashville area, call on Interstate AC Service at 615-832-8500.  We’re here for you.

Posted on 01/21/2018 3:00 PM by Cheryl Austin
Tuesday, 02 January 2018

audio, podcast, Heat blowing cold airWe’ll frequently encounter a caller complaining about their heating system blowing cold air.  We may ask a few other questions but it comes down to this: what temperature is the thermostat set to and what temperature is it reading in the house?  The answer to those questions can often expose the problem without a service call.

Gas Furnace vs Electric Heat Pump

feeling cold, cold air blowing, chilledSuppose the caller tells us that the thermostat is set to 70 degrees and the room temperature is reading around 70 as well, but they still feel cold air blowing from the system.  This is often a clue that this homeowner is experiencing their first winter with a heat pump instead of a furnace - in other words, electric heat rather than gas heat.  Here’s the real issue: Gas heat is much hotter coming out of the vents than electric heat.  A gas furnace puts out 130 to 140 degree air.   In contrast, a heat pump may only put out air at about 85-92 degrees. But regardless of the heat source, both types of heating systems are able to maintain the inside house temperature at 70 degrees.  Our body temperature is normally 98.6 degrees.  Gas heat puts out air that is much hotter than our body temperature, so it feels warm.  Electric heat puts out air lower than our body temperature, so by comparison, it feels cold.  Additionally, because gas heat puts out hotter air, it does not need to blow as hard or as long as electric heat to achieve the same room temperature.  Frequent blowing causes evaporation from the skin which naturally cools the body, and may make us feel chilled.  So, if this is your first winter with a heat pump, and the air temperature is keeping close to what whatever you’ve set the thermostat to, there likely is no problem with your heating unit.  It just might take some getting used to.

Switch Fan to AUTO

Thermostat modes, thermostat settings, fan auto, heat modeHere’s another possibility:  Remember how we said blowing air helps cool you?  In the summertime, it is often helpful to turn the fan setting on your thermostat to “On” – so it runs all the time – rather than “Auto” – where it only blows when the unit kicks on.  But in the winter, you’ll want to set the fan back to “Auto”.  Just like on a windy day, blowing air makes us feel colder than the actual air temperature.  In between the heat cycling on, the air inside the ducts may cool below the “usual” heated air temperature, so if the fan is on all the time, it will be blowing cooler air at you until the heating unit kicks back on.  Avoid a service call by just manually switching the fan setting on your thermostat to “Auto” in the winter.

Service Call? Things You Can Check

But, if the room air temperature is really well below the thermostat setting, then you may indeed have a problem!  The outdoor unit may have iced up, or your system may have a bad reversing value or compressor, or the refrigerant may be low (yes, you still need refrigerant for heat!).  Any one of those things will likely require a service call.  But here are some things you can check and might be able to fix yourself.  Is the thermostat switched to cool mode instead of heat mode?  Turn it off, and then flip it to heat mode.  hole in duct, ductwork leakIf your ductwork goes through an attic, crawl space or basement, are there open windows in those areas?  Does the ductwork have a hole in it or has it become separated from the main trunk?  Those things will need to be fixed before it’s possible to determine whether there is an actual mechanical problem with your heating system.

Not As Warm As You'd Like?

If you live in the Nashville or surrounding area, and your heating unit is not keeping you as warm as you’d like, give us a call at 615-832-8500. We’re here for you.

Posted on 01/02/2018 8:03 AM by cherylaustin
Saturday, 16 December 2017

You’ve probably heard us talk about the benefits of using a programmable thermostat, or have read our head-to-head comparisons of the Nest and Honeywell smart thermostats.  We’ve touted that swapping out your thermostat can be a do-it-yourself project, but, any time you replace a thermostat, you’re left with what to do with the old one. 



what should I doYour first inclination is to place it in the trash – especially if the reason you’re replacing it is that it no longer functions.  STOP!  Did you know that thermostats contain hazardous mercury that can contaminate the environment and can be fatal?  While installing a new smart thermostat helps protect the environment, throwing your old thermostat in the trash does just the opposite!

Since the 1830’s, thermostats have contained mercury – a metal that is liquid at room temperature and gives off vapor if not contained.  The new electronic thermostats do not contain mercury.  Although mercury thermostats are the largest source of mercury in homes, other sources of mercury include CFL and fluorescent light bulbs, batteries, and thermometers.  But there is no concern with exposure to mercury inside these devices, as long as the mercury is contained.  The problem arises when you throw them into the trash: the trash goes through a compactor, and then is taken to a landfill, so it is likely that the mercury bulb within the thermostat will bust at some point, and the mercury will escape.  Mercury does not break down.  It gets into the ground water, our lakes and streams, fish and birds, and becomes concentrated in our food supply, and in people.

Mercury contamination, Health Hazards of Mercury, Toxic mercuryAccording to the World Health Organization, mercury exposure is a major public health concern.  It can result in neurological and behavioral issues, kidney toxicity, and digestive tract and lung issues.  In utero and in children, it affects development, language, memory, cognitive thinking, motor and spatial skills, and attention.  It can be fatal if inhaled or ingested.  

mercury recycling, mercury in trash, banned thermostatsMany states have already taken steps to ban mercury-containing thermostats from being sold or installed.  In most states, including TN, it is illegal to throw out thermostats in the trash.  Although mercury cannot be destroyed, it can be recycled and reused.  However, mercury-containing products cannot be recycled by simply throwing it in your curbside recycling container.  So, what should you do?

Place your old thermostat in a sealable container such as a ziplock bag or plastic tuperware container.  This is so that if the mercury bulb breaks inside the device, its vapors will not be breathed in.

Check online for the nearest hazardous materials drop-off site.

thermostat installation, thermostat recycling But the easiest thing to do is to give it to us or any HVAC contractor.  We are all obligated to recycle the thermostats for you.

So, next time you’re getting your Spring or Fall maintenance visit, give us your old thermostat.  Or better yet, call on us to install a new thermostat for you, and we’ll take your old one with us when we leave.

If you live in the Nashville and surrounding area, call on us at 615-832-8500. We’re here for all your heating and cooling needs.

Posted on 12/16/2017 8:04 AM by cherylaustin
Friday, 01 December 2017

podcast, audio, heating adviceHere is a sample of some of the worst advice we’ve heard over the years when it comes to heating your home. These mistakes may cost you money, damage your system, or sacrifice your comfort.

  1. air filtersAir Filters:  Some folks buy the higher quality air filters – like the ones that filter allergens – and then mistakenly think that since they are higher quality, they won’t need to be changed as often. All air filters need to be changed at a minimum every 3 months to avoid damage to your air handling system. Actually, a case can be made that the higher quality air filters may need to be changed more frequently, since they trap more particles and are apt to get clogged up sooner!
  2. Vacationing:  Many folks try to save money by turning their heat off when they’re going to be away for an extended time. But if temperatures drop below freezing, your pipes could burst causing costly repairs!  Instead, turn the heat down to no lower than about 55 degrees. In fact, it's a good idea to turn off the water to the house (via the main cutoff valve), and then open up all the faucets so there is no possibility of frozen pipes. That's because if the power goes out while you're gone, the heat won't work anyway.
  3. Sacrificing efficiency: Many folks will crank up the thermostat to keep warm. But by making your system work harder than it has to, you’re decreasing its lifespan, which will leave you without heat sooner. Take advantage of ways to increase your heating efficiency like reversing your ceiling fans, opening drapes during the daytime and closing them at night, using a programmable thermostat, unblocking air vents, adding attic insulation, and sealing up air leaks. This will make you feel warmer without having to raise the thermostat as much.
  4. Closing off unused rooms: This is a mistake many homeowners make which only causes more stress to your system. Unless you intend to completely seal the unused rooms (including the air gap under the door) and the return air grille is not located in or near that room, a better solution would be to create a separate zone for that room (see: Is Zone Control for Your HVAC the Answer?).
  5. Using a fireplace or other local heat source to supplement your HVAC system:  Some people think that it will help keep their house warmer if they use their fireplace in addition to their HVAC system. However, the fireplace causes already warmed room air to be sucked up the chimney and creates drafting which actually makes the house colder and makes your HVAC system work harder. Running exhaust fans for an extended period of time has a similar effect.  Furthermore, using the fireplace greatly increases indoor air pollution (particulate, soot, and toxic chemicals in the air, which can trigger allergies). Using space heaters, candles, or kerosene lamps to supplement your central HVAC system also carries the added risk of house fires.
  6. Covering your outdoor unit to protect it from rain and snow:  While the unit is on and operational, it must have good air flow all around it in order for it to operate, and you will damage the unit if you operate it with the cover on. You’ll need to keep the fall leaves off the unit, too!  The only time it may be covered is if it's turned completely off at the circuit breaker. Keep in mind, a covered unit makes the perfect living space for small critters that can gnaw at your wiring and insulation, and it’s also a perfect environment for mold to accumulate.
  7. Skipping maintenance visits:  Annual service is cheap compared to the cost of a breakdown. Having preventive maintenance will keep your system running at peak performance and efficiency (thus keeping you warmer), and will prevent future problems (thus saving you money). Plus, it could detect a potential health hazard, such as a carbon monoxide leak (see our posts Deadly Carbon Monoxide from Cracked Heat Exchangers  and Your Furnace Can Kill You!). Don’t just ignore danger signs like unusual smells or noises – call a professional!  

If you live in the Nashville and surrounding area, call on Interstate AC Service for all your heating needs, at 615-832-8500. We want to help keep you warm and safe this winter! 

Posted on 12/01/2017 7:00 AM by cherylaustin
Saturday, 18 November 2017

It always seems your heat will go out on the coldest day of the year!  Why spend money when you may be able to fix it yourself? This post describes some trouble-shooting and fixes you may be able to do before calling a technician.


1.   Thermostat-related issues:

  • Is the display on your thermostat blank? It could be because it needs a battery, or that the circuit breaker to it has been tripped or you’ve blown a fuse. Reset the tripped circuit breaker, replace the fuse, or replace the battery.  
  • Make sure all the wires going to the thermostat are connected and not loose.
  • Check that the thermostat is in heat mode. This switch can easily get accidentally bumped while dusting.
  • For programmable thermostats, check that it is set to the correct day and time, including the AM or PM designation.  One customer bought a programmable thermostat to save money, with the intent to have the heat backed down while the customer was away at work, and have the heat cranked up at night when the customer was home.  When the customer started freezing at night, they mistakenly thought something was wrong with their heat, when the real culprit was they had the AM/PM designation backwards on their thermostat!
  • If you had a recent power outage, it could be that all of the settings on your programmable thermostat have been wiped out.  Often there is a battery backup in these units, so you may need to change the battery and then re-enter your settings.

2.   Furnace-related issues:

  • If the heat is out and you do not hear the fan coming on, and there is no air coming out of the supply registers, there may be no power to the furnace.  This is often due to someone flipping the switch accidentally while cleaning out the attic or basement (areas where the furnace may reside). The switch often looks similar to a light switch and is easy to mistakenly turn off.  Just flip the switch back, and you should hear the furnace start up within 3-5 minutes.
  • Many thermostats get their power from the same electrical circuit that feeds the furnace system, so if your thermostat is blank, turning on the switch by the furnace may be the solution.
  • Some furnaces have emergency cut-off switches that are activated when a door or service panel is removed. If the furnace door is not closed properly (such as after a filter cleaning), or has been accidentally bumped open, the cut-off switch will prevent the furnace from coming on.  Verify all access doors are properly closed.
  • If the fan runs, but the air coming out is cold, you have a problem with the furnace (or heat pump) itself, and may need a service call. This may not be something you can tackle yourself.

3.   Electrical Issues:

  • If the switch is on to the furnace and it still doesn’t come on, it could be that the circuit breaker or fuse to the furnace (or heat pump) is tripped or blown.  Reset the breaker by turning it all the way OFF, then back ON. If the fuse for the furnace is blown, be sure to replace it with the same size and type of fuse.
  • If a breaker keeps tripping or a fuse keeps blowing, contact a qualified electrician to inspect your system to determine why you are having problems.

4.   Filter issues:

  • A dirty air filter restricts air flow, and the system will work harder and build up pressure. Some newer, more efficient furnaces are sensitive to this pressure build up and turn off before the dirty filter can cause further damage. At the very least, a dirty, clogged filter will reduce the heat output of your system. The simple solution is to change the filter! 
  • Don’t try to just vacuum the existing filter and re-insert it. The material inside the filter will still be saturated. Just place the old filter in the trash and insert a new one each time… at least every 3 months.

If none of these DIY fixes addresses your problem, give us a call at 615-832-8500.  We’re always here to help!


Posted on 11/18/2017 5:12 AM by tony anderson
Wednesday, 01 November 2017

podcast, audioHeating equipment is one of a homeowner’s major expenses.  The efficiency of your furnace can make a big difference in your energy bills. A new furnace will save money on your heating bills, be safer, and greener (better for the environment).  Our best advice is to plan ahead!  Don’t wait until the dead of winter and your heat has gone out to start thinking about replacements. In fact, you’re likely to get the best pricing on a furnace in the spring or fall.

Average Lifespan of a Furnace is 15 Years

aging HVACDon’t know how old your furnace or heat pump is?  Open the cabinet and look for dates.  Write down the model number and search the Internet to find an approximate date of manufacture. If your furnace has a standing pilot light instead of electronic ignition, or its AFUE (Annualized Fuel Utilization Efficiency) rating is less than 80%, this is a sign that it is obsolete and wasting energy. If your heat pump has a HSPF (Heating Season Performance Factor) of less than 7.7, you should consider replacement. If you already know your existing furnace won’t make it through another winter, or you’re facing major repair bills on a furnace at least 15 years old, you should buy a new one now.

Types of Systems

split system, HVAC furnaceGenerally, you’d want a central heating solution, unless you are forced into a local heating solution due to not having any ductwork.  For a local solution, a mini-split system is ideal because it does not require ductwork and is extremely efficient (see our previous posts on mini-splits here: 1, 2, 3).  For central heating, you can go with a split or packaged system.  Split systems are most common, and have a condensing unit and coil that sits on top of your furnace.  They have an indoor component and an outdoor component, hence the term “split.”  Packaged units mean it’s all in one unit and that unit can sit outside.

What Fuel Type Is Best?

gas furnaceNatural gas is the least expensive way to heat. Oil or propane furnaces are an option only if your home does not have gas lines.  Electric furnaces (heat pumps) are more efficient than natural gas, but producing heat from electricity is more expensive. A heat pump can also act as an air-conditioner in the summer, so can be used year-round.  If you have a natural gas furnace, you’ll still need another option for air-conditioning. Some systems are dual-fuel systems, which use a heat pump (electricity) to heat and cool your home, and a gas furnace which serves as the back-up heat source and helps deliver the heated air produced by the heat pump.

Size: How Large a System Should You Buy?

Don’t just blindly get the same size that was originally in the house, as additional space may have been added over the years. In order to size a system appropriately, a load calculation must be done, taking into consideration the square footage of the home, ceiling height, shade around the home, insulation, types of building materials, and the numbers and types of windows and doors. If you get a system that is too big or too small, it won’t work well (it won’t provide good temperature and humidity control), will not be efficient (you won’t see the fuel cost savings you’d expect from a new system), and will break down sooner.

Efficiency is the Key

AFUE, Energy Guide, EfficiencyAlways go with the most efficient furnace you can afford, the one with the highest AFUE number (Annual Fuel Utilization Efficiency rating).  This is the number on the yellow “Energy Guide” label on the unit.  Just remember, the higher the AFUE, the lower your monthly heating costs.  Energy Star, efficiency

Look for the ENERGY STAR® label and certification on the unit to be assured it will meet government efficiency standards. Other criteria to look for include:

  • A variable speed blower motor.  This will save energy and reduce noise.  A fixed-speed blower blows hot air into the house full force for a few minutes, then shuts off – often resulting in pockets of warmer and cooler areas.  A variable speed blower blows faster when it’s colder outside, and then slower for longer periods, providing quieter and more even, comfortable heat.
  • A sealed combustion chamber: this not only makes the system quieter and more efficient, but safer, too, as it avoids the possibility of introducing combustion gases into your home.
  • A second heat exchanger with condensing flue gases and/or 2-stage gas valves.

Installation: What to Expect

Installation takes about a day, but can take several days if your ductwork also needs to be replaced. Never compromise on installation quality.  A poor installation may mean the unit won’t perform at its potential and could cost you more to run. Be sure your new system is installed by a certified licensed HVAC contractor with a proven track record of successfully installing similar systems to yours.

A Good Time to Consider Options

ThermostatAny time you’re considering a major replacement, may also be a good time to consider other options.  For example, installing a multi-zone system will allow you to control multiple areas of your home independently with separate thermostats without buying separate systems. Getting an electronic programmable thermostat will give you more precise control of temperature and could lower your energy bills by up to 30%.

Should you replace your heating and cooling systems at the same time?

In general, the answer is yes.  This is because mismatched systems may not deliver the energy efficiency or performance you expect, and could contribute to service problems later on. A central system uses the same ductwork for both heating and cooling so you want to be sure all parts work together.

Is Maintenance Necessary on a Brand New System?

furnace maintenanceYes. But only if you want it to last a long time, not have unexpected breakdowns, maintain its efficiency and perform at peak levels.  Check out our Fall Maintenance Guide (download here) and get a yearly service contract.  That way, you’ll know if there has been a recall or if a part is covered by warranty when it goes go out. Some warranties can be invalidated if you cannot prove the unit has been under a service contract.


Do not make a decision based on upfront pricing alone.  Check to see if there are manufacturer’s rebates or incentives you can take advantage of, or low interest financing, or tax credits.  Having a reputable HVAC contractor is more important than the price.  You’ll want to feel confident the system will be sized appropriately, installed correctly, and that the company will be around to offer on-going maintenance and support. A longer warranty should also be factored in, as it can translate into cost savings in the long run.

Selecting a Contractor

HVAC contractorYou should get multiple bids from reputable, licensed, NATE-certified HVAC installers. Make sure they inspect your home and be wary if they give you an estimate over the phone.  Get the estimate in writing and understand what’s included.  Ask about warranties and service agreements. Remember the best value may not come from the contractor with the lowest price. 

Now’s the time to focus on energy improvements in your home! If you live in the Nashville or surround area, give us a call at: 615-832-8500. Interstate AC Service will help you with all your heating and cooling needs.

Posted on 11/01/2017 8:14 AM by cherylaustin
Sunday, 15 October 2017

We all try to make our dollars go farther and last longer.  Big expenditures – like a new HVAC system or a major HVAC repair – can break the budget… and who has time for that anyway?  Here are some true stories from customer experiences we can all learn from.


Case #1:  A married couple, Dan & Cheryl, decided to sell their house their 18-year-old house.  The buyers were apprehensive about the original HVAC unit, and figured it would never pass inspection… in fact, they were hoping to use the aged HVAC unit as a bargaining chip to force concessions from the owners.  To the buyer’s and inspector’s surprise, this 18-year-old HVAC passed inspection with a totally clean bill of health!  Here’s what Dan & Cheryl did, and you can, too!

  1. Get regular fall and spring tune-ups.  This will help keep your system running like new, increase efficiencies and keep your daily heating and cooling expenses low.  Plus it will spot problems when they can be easily fixed, before causing a major outage.  For both time and money, having regular system maintenance can only work in your favor.
  1. Change your air filters regularly.  Set automated reminders and never use a filter longer than 3 months.  Never try to just vacuum the filter and reuse it!  The microscopic debris imbedded deep inside the filter can harm your system over time. During every filter change, clean out the return air ducts and grill with a cloth or vacuum, too.
  1. Keep the air vents open and clean. Never block vents with magnetic covers, furniture, or anything that would impede airflow.  This causes extra strain on the HVAC unit.  During fall and spring house cleaning, clean out the vents using a cloth or vacuum to remove any dust or debris.  To see how, check out a previous video we did illustrating this.
  1. Keep the indoor and outdoor units free of debris.  This means cleaning off the leaves throughout the fall, keeping grass clippings out of the unit, and keeping the area around the inside and outside units free of obstructions.
  1. Add a whole-house electronic air cleaner.  This helps keep the heat exchanger free from debris which over time causes cracks, leaks, expensive repairs, and could even cause carbon monoxide poisoning. 

Case #2:  Now, let’s look at the experiences of another homeowner named Sherrie.  She rented out her home for a year prior to selling it. At that time the renters moved in, the HVAC unit was just 8-years-old.  A year later, Sherrie was in for surprise!  The renters had not changed the HVAC filters at all during the entire years’ time, and it had burned up the HVAC unit to where it would no longer come on.  They also had not kept up the maintenance on this heavily wooded lot, and the HVAC unit was covered in debris.  Sherrie had to pay nearly $8,000 for a new HVAC unit before it could pass inspection, thus taking a big chunk out of her sales’ profits.  Ouch!  That is a hard way to learn that the most important thing anyone can do to prolong the life of their HVAC unit is to change the air filters!

Whether you’re getting ready to sell your house and don’t want to be faced with a failed inspection – or you’re  a conscientious homeowner, looking to make the best use of your time and money, following these steps will help prolong the life of your HVAC system.

If you live in the Nashville or surrounding area, rely on Interstate AC Service for all your HVAC maintenance needs.  Call us at 615-832-8500. We’ll help you get the most life out of your HVAC system.

Posted on 10/15/2017 8:30 AM by cherylaustin
Monday, 02 October 2017

audio, podcast, fans

In the fall and spring of each year, fan direction, fan rotationremembering to change the direction of rotation of your ceiling fans may make a bigger difference than you think!  Knowing which direction they should rotate can sometimes be trickier than it seems. Suppose the directions say the blades should turn clockwise, does that mean clockwise when you’re looking down the shaft of the fan from the top?  Or does it mean clockwise when you are below looking up at the fan? They’re not the same! So here is the definitive way to know how to set your fans for any given time of year or situation.

Heat Rises

First, you need to remember one basic principle: heat rises.  Whether it is summer or winter, whether you’re running your air-conditioner or heat, the warmest air will always tend to pool toward the ceiling and the cooler air will always tend to pool towards the floor. This is even true if your air-conditioning vents are set in the ceiling or your heating vents are set in the floor.



Fan Blades Are Angled

If you look at the fan blades, you’ll notice they are not set exactly horizontally in the fixture. They are angled slightly. If you imagine the blades as big spatulas mixing up a cake batter, you can envision that if the blade moved in one direction, the strokes of the spatula would be angled upward.  Moving in the opposite direction, the spatula strokes are angled downward.

Where Do You Want the Air to Go?

In the summertime – or any time you are feeling too warm – you want to feel a breeze of cool air.  The best way to do this is to be sure the fan blade is “scooping” up the cooler air below and wafting it upwards. In other words, the “spatula” should be stroking upwards.  In the wintertime – or any time you are feeling too cool – you want that warm air trapped up by ceiling to come down and surround you.  So you want the fan blades to be pushing the air downward.

How Do You Change It?

fan switch, change fan rotationYou are never really changing the angle of the blades – they stay stationary inside the fan fixture. However, there is usually a small, two-position switch somewhere near the fan motor (towards the center mechanism, not on the blades).  Turn the fan on and observe which way it is “scooping” the air: upwards or downwards.  If it needs to be changed, turn the fan off and wait for it to come to a stop. Then flip this switch in the other direction, and turn the fan back on.  Never try to flip this switch while the blades are still rotating!

Use Fans Year-Round

Most people have no problem using ceiling fans in the summer to create a “wind chill effect” – in other words, to increase evaporation from the skin, which makes us feel cooler.  But many avoid using their fans in cooler months for that same reason.  But if your ceiling fan is spinning the correct direction (as described above) you can save as much as 15% on heating costs... just turn the fan to a lower speed setting to minimize the wind chill effect.  Look at it this way: you’ve already paid to heat the air that is now trapped near the ceiling… why not spread it around to help warm the people in the room? This is even more critical if you heat the room with a form of localized heat – such as a space heater or wood-burning stove.     

Saving Energy, Money, and Feeling More Comfortable

By having fans rotating the correct direction at any given time of the year, you can save money on your heating and cooling costs because you’ll be saving energy.  You’ll be able to set your thermostat higher in summer and lower in winter and still feel comfortable.  By moving the air, fans help to “mix” the various layers of cooler and warmer air that naturally stratify due to physics.  This will help your HVAC system run more efficiently and increase your comfort, no matter the season.

Important Tips

If your ceiling fan does not have a way to “winterize” it (e.g., to change rotation direction), consider replacing it with a model that does. Also, don’t forget to clean the fan blades and replace any burned out light bulbs (if your model has lights) while you’re flipping that switch. Ceiling fans should only be used in rooms with ceilings at least 8 feet high.  For optimal performance, the fab blades should be 7-9 feet above the floor and 10-12 inches below the ceiling.  Larger ceiling fans can move more air than smaller fans, and a larger blade will also provide comparable cooling at a lower velocity than a smaller blade.  Some large rooms are best served by installing 2 or more ceiling fans. We recommend fans that have earned the EnergyStar® label - they move air up to 20% more efficiently than standard models.

air filtersHere’s another tip for the changing seasons: Remember to schedule an HVAC maintenance tune-up to ensure there are no surprises later in the dead of winter or the heat of summer.  And, we can’t preach it enough: the most important thing you can do to keep your HVAC system running more efficiently and prolong its life is to change your air filters. Set up reminders every 3 months and never miss a filter change.

If you live in the Nashville or surrounding area, Interstate AC Service can get your HVAC system ready for whatever lies ahead. Call on us at (615) 832-8500.

Posted on 10/02/2017 7:26 AM by cherylaustin
Friday, 15 September 2017

Fall has come to mean football and tailgating.  But it also means it’s time to get ready for heating season.  Having a fall maintenance check now will help ensure you stay warm as temperatures drop in the months ahead.

We tag along on a typical fall maintenance check done by Lance Waterbarger, technician for Interstate AC Service.   In this video, Lance checks on a 19-year-old Ruud system installed in a customer's attic. The air handler uses both a heat pump and a bank of two electric heaters.


Here are some of the points Lance makes as he performs his fall preventive maintenance service.

  1. The voltage across the capacitor is checked.
  2. All wiring connections are checked. In this unit, a transformer was replaced at some point in the past and a fuse was added to protect the transformer from damage in the event there is a short in the low voltage circuits.
  3. The blower motor bearings are checked.
  4. The heat is turned on and put it in emergency heat mode to test the heat banks. The amperage draw is checked for each heater. There is a short time delay between the first and second heat banks coming on, to avoid an excessive amperage draw that would dim the house lights.
  5. The heat bank sequencer is checked for proper operation. Generally, you'll have a 3- to 5-degree swing between first and second stage heat. When the first stage comes on, it goes into defrost mode in order to melt the ice on the outside coils.
  6. Lance checks that the heaters come on during the outside unit defrost mode.
  7. He verifies that the outside unit reversing valve works in defrost mode. The outdoor coil freezes up in heat mode and there is a sensor on the line that will indicate when it needs to thaw the coil. It has a timer or a demand control board that will switch the reversing valve, turn the heaters on and turn off the outdoor condensing fan. This traps the heat and melts the ice off the coil. When the sensor senses that the coil is approximately 50-55 degrees, it will kick in automatically back to your regular heat cycle.
  8. Other checks (not seen in this video) which are part of Interstate AC Service’s preventive maintenance include:
  • Inspecting all air filters.
  • Checking whether the blower belts are worn out.
  • Checking the thermostat for proper operation and settings.
  • Checking and cleaning the condensate drain.
  • Checking all safety features on the unit.
  • If it is a gas furnace, a check of the air supply and flue is done, as well as the burners, fuel igniter switches, inducer motor, and heat exchangers.

A fall maintenance check will not only keep your system running more efficiently and reliably through the winter, but could save your life by preventing a deadly carbon monoxide leak.  So, if you live in the Nashville and surrounding area, call on Interstate AC Service today and schedule your fall preventive maintenance visit at 615-832-8500.

Posted on 09/15/2017 8:00 AM by cherylaustin
Friday, 01 September 2017

finger-pointingaudio, podcastWhether it’s your HVAC unit, your car, or some other device, it’s easy to feel caught in the middle by “finger-pointing” from different service companies. See if any of these sound familiar:

  • Company B tells you they need to install a new part that Company A just recently replaced.
  • Company B says that Company A did something wrong and they are having to un-do it or re-do it.

What should you do?  You’re probably not a technical wiz about the issue – that’s why you called a service technician to begin with! 

The Importance of Relationships

Having a reputable company with whom you have established a relationship provides piece of mind. By having the same company service your HVAC unit year after year, and not just going with whichever company is running a special this month, offers some advantages. Here at Interstate AC service, we keep all your service records on file.  That way, we know what’s been fixed or replaced and when, and may be better able to judge whether it was a defective part rather than a poor installation. If you have a consistent relationship with a company that does this, you may be able to eliminate much of the finger-pointing.

Service Contracts

service contractHaving annual service or maintenance contracts can go a long way to alleviate the “caught in the middle” trap.  If the same service technician(s) come to service your HVAC unit year after year, they learn your system, they know what was done last time and what your system is scheduled for this time.  They can watch your system as it ages, and head-off failures before you experience a breakdown.  In many ways, it’s similar to taking your car to the same mechanic each time for service: they get to “know” your car.  So, besides all the other benefits of service contracts (see our previous post), sometimes the peace of mind service contracts provide are worth it!   

The Aspect of Trust

trustNo matter what a service technician is telling you, it comes down to trust… especially when you do not have first-hand technical knowledge in the field.  When you have a serious medical problem, you want to find someone you trust to advise you: someone who has good credentials, is noted in their field, has high success rates treating your type of illness, etc.  When picking an HVAC company, you want one that is honest, trustworthy and reputable, has experience with the type of equipment you have, and has many satisfied customers. Then, when the service technician advises you on some aspect of your HVAC system, you’ll feel confident you can trust their advice.

Moral of the Story

Service technicianFind a service company you can trust, establish a relationship with them, and get a service contract on your equipment.  These are just a few suggestions to help you feel more empowered and less likely to be caught in the middle.

Posted on 09/01/2017 6:00 AM by cherylaustin
Tuesday, 01 August 2017

CooliListen, podcast, air conditioningng an empty house – either when you’re gone during the day at work, or when you’re away for an extended vacation – seems like a bad idea since it uses electricity and energy, and wastes money. So, it’s natural to assume that the best way to save money is to turn it off when not in use, right?  Not so! Here’s why:

humidity, window condensation, indoor moldWhile you’re gone, the house heats up, but it does so unevenly – with some areas or materials retaining pockets of cooler air and others having pockets of warmer air.  This can cause condensation inside the walls, around pipes and around windows, while indoor humidity rises.  In Tennessee, it’s like we always say: it’s not the heat, it’s the humidity!  The increased humidity in your home attracts bugs and greatly accelerates mold growth.  Over time, this moisture and mold can damage a house, causing fowl smells, wood deterioration and warping, buckling of wallpaper, peeling paint, and can damage sensitive artwork, electronics, and bottled wine.  High humidity also greatly increases allergens in the air – bacteria, mold, fungus, and dust mites -  which get deposited in your living space.  Remember: the number one thing air conditioning provides is dehumidification!

What’s the Solution?

thermostatThe best solution is to turn the air conditioning down a few degrees but not completely off when not in use.  If you’re going to be gone for less than 12 hours, we recommend turning the thermostat up by no more than 4-6 degrees.  This way, you won’t come home to a humid, stuffy house and your air conditioner will not have to work very hard to cool the house down to your “normal” setting.  On the other hand, if you’re going away on vacation for a week, we recommend turning your thermostat up by no more than about 7-10 degrees.  This will allow you to save the maximum amount on cooling without risking damage from humidity.  A good rule of thumb to keep humidity at bay is to never set your thermostat higher than 82 degrees.


Programmable Thermostats to the Rescue!

programmable thermostatHere’s where having a programmable thermostat is ideal.  You can set it to automatically be a few degrees higher during the portions of the workday when you are away, so you won’t need to remember to do this manually each day. Most thermostats also have an “away” setting you can use while on vacation.  Don’t want to come home to a hot house?  Many smart thermostats give you the ability to reset the temperature remotely, so you can turn down the temperature a couple of hours before you return.


Other Summer Vacation Tips

carpet cleaning, steam clean, summerDo not steam clean carpets during the summer. This will increase humidity and cause moisture to be retained in the carpet and padding (especially if you’re turning the thermostat up!), and thus increases the mold and allergen problem.  It’s best to clean carpets during the winter months, when humidity is lower, and room heat can aid in drying the carpet and pad more quickly.


exhaust fanDo not leave exhaust fans on while you’re on vacation.  This only serves to exhaust the already cooled air and makes your air conditioner work harder.


houseplant, humidityRemove any standing water in the house – whether from a pet’s water dish (assuming you’re not leaving your pet behind), or in saucers around plants.  Water your plants the night before and pour out any excess water just before leaving.  Many plants are able to take in moisture from the humidity in the air, and leaving standing water around only attract bugs and mold… especially if you are raising the thermostat up several degrees.


Check out our many posts for more helpful tips to get the most out of your heating and air-conditioning year round.  If you live in the Nashville and surrounding area, Interstate AC Service is here for you!  Call on us at 615-832-8500.

Posted on 08/01/2017 6:44 AM by Cheryl Austin
Saturday, 15 July 2017

Here in Middle TN, we use our air-conditioners more months of the year than our heat. In fact, the average electricity consumption for Tennessee households is 33% higher than the national average (EIA, 2015 report) and is among the highest in the nation! So anything that can help keep us cool while also saving money is a welcome relief!  Here are some tips to help you stay cool and save money during the summer:




First, let’s look inside your home…

  1. Install a programmable thermostat:  According to the US Dept of Energy, this can save you hundreds of dollars per year – and not just during the summer months, but year-round!
  1. Use LED lights:  LED bulbs are 75% more efficient because they eliminate most of the heat produced by traditional lighting… which means your air-conditioner doesn’t have to work as hard.
  1. Circulate the air:  Use a fan to keep the air moving, especially on upper floors.  Moving air causes faster evaporation from the skin and has a cooling effect - making it feel up to 8 degrees cooler - without touching that thermostat.
  1. Smart cooking:  Decrease indoor heat by using a microwave oven, rather than your thermal oven or stove, whenever possible.  Better yet, eat foods like salads that do not require cooking.  If you must boil or bake, do so in the evening when it’s cooler.
  1. Use exhaust fans wisely:  Make sure you turn on the vent fans in areas that create moisture, like the shower, bathroom, kitchen, and laundry room, and turn them off as soon as most of  the moisture has dissipated, so you’re not exhausting cold air to the outside!  If you do not have exhaust fans, consider installing some.
  1. Replace air filters:  every 3 months or more frequently, if needed. If you have spring and summer allergies, buy the higher quality air filters that can filter out pollens.
  1. Keep the sun out:  Use drapes, blinds, shades or screens to block the sunlight, especially during the hottest part of the day, or when you’re not at home.
  1. Get a tune-up:  Regular maintenance by your HVAC system professional will keep your air-conditioning running at optimal efficiency and will address potential failures, thus saving you money in the long-run. 
  1. Optimize air flow:  Make sure all supply and return vents are open and unblocked. Keep all doors and windows closed and make sure they’re well-sealed.  Seal any leaks in the ductwork and around windows.
  1. Insulate the attic:  Adding attic insulation, while making sure the attic is well-vented by keeping the eaves unobstructed, is the best investment you can make. And it pays for itself by saving you money year-round.

Now, let’s see what can be done outside your home to keep you cooler and save money….

  1. Clear it out: Keep the area surrounding your outdoor unit clear of all obstructions 2-3 feet all the way around. Don’t allow the lawn mower to discharge grass clippings into the unit. Weekly, remove debris such as leaves, pollen, and twigs from the top and sides of the outdoor unit, and keep plants and shrubs trimmed. If the outdoor unit is crowded by a fence or shrubs, or if the bottom few inches is buried under mulch, air-flow will be restricted, which decreases your air-conditioner’s efficiency, reduces its life span, and damages the unit.
  1. Provide shade: Keep your outside unit in the shade as much as possible. This can boost air conditioning efficiency by up to 10%.  
  1. Light colors:  Just as wearing light-colored clothing helps keep you cooler, painting the exterior of your house a lighter color, or having a lighter colored roof will keep the home cooler. Although your house won’t absorb as much heat in the winter, the net energy savings in summer far exceed the energy penalty in the winter, especially in our region of the country.
  1. Upgrade your windows. Installing double or triple pane windows will save energy year-round. But, if you can’t do that, try adding a reflective window film to your existing windows.  This will reflect heat before it can come through the glass, and it’s transparent, so you can still see out.
  1. Update your HVAC: If your HVAC system is more than 15 years old, you can cut your utility bills by up to half if you switch it out for one of the new higher efficiency units. Or use some of the newer technologies, like a mini-split, in certain areas of your home.

At Interstate AC Service, we’re here for all your heating and air-conditioning needs.  If you live in the Nashville or surrounding area, call on us at 615-832-8500.  Let us help you keep cool this summer.

Posted on 07/15/2017 7:17 AM by Cheryl Austin
Saturday, 01 July 2017

 audio, podcast, listenAs the summer heats up, our thoughts turn to cooler technologies.  In this post, we highlight some of the latest revolutionary and disruptive technologies when it comes to cooling.  Here is just a brief taste of what’s to come in the not-too-distant future:

Thermoelectric Cooling (TEC)

Thermoelectric cooling, TEC wine coolerThese devices use the Peltier effect and solid-state technology to create a thermoelectric heat pump that can power a refrigerator or similar cooling device (wine cooler, window air conditioner, etc.) with no moving parts, no compressors, no toxic refrigerants, and no noise.  Traditional cooling devices have up to about a 10% efficiency, while TEC devices have upwards of 30% efficiency, resulting in up to 75% energy savings.  Furthermore, a device such as this can be run in reverse to create heat.  This paves the way to have room-by-room radiant heating and cooling.  Advantages of these devices include: a very long life, invulnerability to leaks, no refrigerants, precise temperature control (within fractions of a degree), small size, and flexible shape.  To find out more, see Phononic, and their Evolve line of refrigeration products.

“Plastic Wrap” for Buildings

plastic wrap, radiant coolingBased on the principles of passive radiant cooling, engineers at the University of Colorado Boulder have created a highly reflective film – polymethylpentene plastic with embedded silicon dioxide and silver coating – that can be used to “shrink-wrap” buildings.  This material emits infrared radiation while not absorbing solar radiation.  Even if only used on a typical roof, it can cool down a single-story home enough to keep it cool during the summer.  You can get a ton of cooling capacity (12,000 BTU per hour) with about 400 square feet of this film (sufficient for 1,000 square feet of floor space).  With zero energy consumption and costing only 50-cents per square yard, it is a promising technology.  But lots of questions remain, like how this might work in humid climates (like Middle TN), and how long the film will last.  Find out more at Energy Vanguard and here.

Thermal Air-Conditioning

Chromasun has created an air conditioner that uses solar power supplemented by natural gas, which totally eliminates the need for electrical power altogether, thus making it very cost-effective.  Plus, by incorporating Chromasun’s unique MCT solar panels (see also our post on Solar Air-Conditioning), the demand for natural gas is greatly reduced.  These systems work off-grid, have few moving parts (no compressors), are reliable and efficient. They are currently in use in Australia and have some projects starting in the U.S.

Magnetic Cooling Technologies

Researchers at GE are using magnetocaloric effects – changes in an external magnetic field that cause a change in temperature – to create the next crop of refrigeration devices. This technology uses no chemical refrigerants (water is the heat transfer medium), no compressors (replaced by magnets), is quieter, and is 20-30% more efficient than what is used today. GE expects to have magnetocaloric refrigerators on the market by 2020, so can a magnetocaloric-based HVAC system be far behind?

Sensor-Enhanced Systems

Honeywell Wi-Fi, Smart ThermostatCurrent HVAC technologies have been taken to new heights through the use of various sensors.  Here are just a few examples. Motion-sensors allow automatically turning off (or lowering) AC use when a room is unoccupied.  Smart thermostats allow auto-sensing, anticipation of demand, remote control and monitoring via a mobile phone app. Ecovent allows remote-control of vents in each room, opening and closing them as needed, to direct airflow where it’s needed. Fully-automated smart home systems now integrate a home’s HVAC system with its lighting, security, entertainment, and household appliances to increase comfort.  The best part of these sensor-enhanced systems is that they are readily available on the market today and can help save energy and money.

Whether you are looking to update your HVAC systems or get more life out of your existing HVAC system, know you can rely on Interstate AC Service for all your heating and cooling needs.  If you live in the Nashville or surrounding area, please call on us at 615-832-8500.  We’ll make sure you stay cool this summer.

Posted on 07/01/2017 7:14 AM by Cheryl Austin
Thursday, 01 June 2017

There will come a time in the life of every HVAC system when it will need to be replaced. See our post on repair or replace to get tips on how to tell whether your unit is a candidate for replacement. Once that decision is made, it is wise to get a couple of quotes.  Replacing an HVAC unit is definitely not a do-it-yourself project!  It takes an experienced estimator, specially trained installers, and special tools. Plus, in most shops, installers are not repair technicians, as different skills are involved. In this video, we follow along while one homeowner gets an estimate to have the HVAC unit replaced during the remodeling of a 1950’s era house in West Nashville, and a second homeowner in a 1928 home has their second floor unit replaced.


  1. The first step is to perform a survey to be able to estimate the work to be done. Tommy Gentry, Service Specialist, has a conversation with the homeowner.
  2. When the survey is complete, Tommy writes down all data and gives the homeowner a price. Once the homeowner accepts the price, Tommy makes arrangements for the installation through the scheduler, allowing for all needed parts to be available, and on a day convenient for the homeowner. In this second case, it was 3 days from the date of the estimate until the job was completed.
  3. The truck arrived at 8:30am loaded with all the parts and gasses required. The HVAC unit being replaced was on the second floor of the house. Care was taken to lay down cloth mats over all the carpets and floors in the HVAC unit’s path.
  4. Next, the refrigerant was removed from the outside unit with an electric pump, and loaded into a recycle can. A pressure meter is used to determine when all the refrigerant has been removed. It is illegal to let refrigerant escape into the atmosphere due to its harmful environmental effects. This refrigerant, called R-22, can be cleaned and used for repairing older units. New HVAC units use a different type of refrigerant, R-410A, which is more environmentally friendly. Since federal law has phased out production of R22, making prices skyrocket, it is worthwhile to capture it so it can be recycled.
  5. Next, demolition of the inside unit began. The power was turned off, the power wires to the unit were cut, and the thermostat was disconnected. It was now safe to cut the copper refrigerant pipes. All pieces of the old unit were removed and carried out.
  6. The new inside unit was installed and all the connections were made. A special propane torch was used to make the copper refrigerant line connections.
  7. The outside unit was completely disconnected and the parts were carried away.
  8. The old HVAC base pad was removed. The ground was leveled underneath and a new base pad was installed that was much sturdier than the old one. Having a level pad is essential to the HVAC unit’s operation.
  9. The new outside unit was installed on the new base pad, and the power and control wires were connected. As before, a propane torch was used to connect the copper refrigerant lines.
  10. Now it was time to test the refrigerant lines for leaks. Nitrogen under pressure was introduced from a container. Nitrogen is an inexpensive inert gas. It is used for testing rather than using actual refrigerant – in this case R-410A refrigerant - because if there is a leak detected, it would all have to be removed, the leak fixed, and fresh expensive R-410A installed. In his case, there were no leaks so the job continued.
  11. The electric pump was used to remove the nitrogen and the pink container R-410A refrigerant was installed.
  12. The new system was tested in both heating and cooling modes, and worked really well.
  13.  The last step was to load all the trash on the truck and haul it to the recycle yard.

Let Interstate AC Service help you make wise investments when it comes to heating and air-conditioning. If you live in the Nashville or surrounding area, give us call at 615-832-8500.


Posted on 06/01/2017 7:48 AM by Eddie Hutton
Monday, 15 May 2017

audio, podcast, Solar ACSunlight is a free and limitless source of energy. Solar energy produces no air pollution or hazardous waste. Solar-powered air-conditioning makes sense since it’s typically hottest when the sun is shining… and that’s when air-conditioning use is most in demand! Switching to solar could reduce your heating and cooling costs by half. 

Solar energy, residential solar, solar panels, photo-voltaic cellsSolar air conditioning refers to any cooling system that uses solar power, which is typically supplied by photo-voltaic (PV) cells, engineered into solar panels. Solar has been around a long time, and many products are now in the 4th (or later) generation.  They are available for both residential and commercial applications. Here are just a few of the types of solar air-conditioners to choose from:


Solar window unit, Air-conditioning, off-gridOff-Grid: Units that run 100% on solar power run on DC power. These are referred to as “off-grid” because they do not require power from the utility company, e.g., they don’t have to be plugged in. An example of this type are solar-powered window air-conditioning units. They operate on DC power only (from solar panels), and use external battery backup (usually good for about 8 hours operation). The battery is so that the unit will continue to function even when the sun is not shining, like at night. A window unit is expensive – $2-3,000 – but it can be used totally “off-grid” which means there are no energy costs during operation.

Solar, mini-split, hybridHybrid Systems: Hybrid systems use solar power when available and supplement that with regular electricity (AC power) as needed, and do not require batteries. During the day, solar power provides 90% of the system’s electricity. At night, it switches over to regular grid power. Examples of this type include room-sized/area-sized units, like a mini-split, or whole-house units, like a hybrid heat pump. One advantage of hybrid systems is that they can also provide heat during the winter.  [Check out our previous posts on mini-splits: What You Need to Know About Mini-Splits, Cooling an Add-on Space, Saving Energy and Improving Comfort] .

Lennox, SunSource, Hybrid HVAC, Solar-readySolar-Ready Systems: These are systems made like “traditional” central air-conditioning units, in that they use 220V AC power, but some of the electricity feeding it can be obtained from solar panels. The Lennox SunSource Home System is one such system. The more solar panels you add (from 1 to 16) the more money you can save in energy costs. You can start small and expand over time, adding other appliances, such as the home’s water heater, making a total home energy system.


There are many misconceptions when it comes to solar. For example:

  • Solar panels do not have to be in full sun to operate. They also operate in partial sun or shade. 
  • Solar panels do not have to go on the roof. They can go just beside the outdoor unit. 
  • Hybrid solar units are not bigger than normal air conditioners. In fact, because of their more efficient design, the compressor can actually be smaller than in a traditional unit. And a smaller compressor consumes less electricity!
  • Solar units are actually more efficient the hotter it gets outside, because more energy is collected in the thermal hybrid collector.
  • Installation costs are comparable to that of conventional units, and prices of solar units have come way down.
  • Using solar does not compromise comfort in any way, and the units do not look awkward or obtrusive. In fact, according to the U.S. Department of Energy, National Renewable Energy Laboratory, a solar-powered unit will increase your home’s value substantially and can help your home sell faster!

Advantages are Environmental, Economic, and Comfort

There are numerous advantages to solar.

Eco-friendly, Energy Star, environmental, Solar
  • Solar air-conditioners are quieter than traditional units. The ones that run on DC power – such as the hybrid mini-splits – are so quiet that you can walk right up to it and not even know it’s on.
  • Solar units last a long time. Most have at least a 10-year warranty (with some parts having more), and some manufacturers have performance warranties of up to 25 years.
  • Most hybrid or solar-ready units offer seasonal energy efficiency ratios or SEER values in the 21-26 range, as compared with traditional HVAC units which have SEER values around 14.  [See our post: What’s your SEER? Does it Matter?]
  • Solar units are typically Energy Star certified, very efficient, and prevent greenhouse gas emissions.  Plus, they use the new R-410A refrigerant, which is more environmentally friendly.

ROI, Return on investment, payback, solar costROI: Fast Payback

The payback period for a complete system (solar-powered heat and air) is about 2-5 years. With tax credits, the cost of installation can be paid for within the first 6 months of operation! Plus, many vendors offer interest-free financing. The federal solar tax credit, also known as the investment tax credit (ITC), allows you to deduct 30% of the cost of installing a solar energy system from your federal taxes. The ITC applies to both residential and commercial systems, and there is no cap on its value. The 30% tax cut was extended through 2019, and then gradually decreases each year from 2020 through 2022, where it levels off at 10%. Solar costs, make money, selling energy back, ROIWhat’s more, a solar-powered home can actually earn money: if your house is not using all the power it is generating, you may be able to sell excess power generated back to the utility company!

It is easy to see that if you get tax breaks for installation, the system saves you half on your energy bills and you can sell energy back (making money from the system throughout its lifetime), that a 2-5 year payback can actually be quite realistic.

**Interstate AC Service is not a reseller or installer of solar panels.

Count on Interstate AC Service to help keep you up-to-date on the latest technologies. If you live in the Nashville & surrounding area, know you can rely on us for all your heating and air-conditioning needs.

Posted on 05/15/2017 8:10 AM by Tony Anderson
Monday, 01 May 2017

Interstate AC Service has expanded and renovated its facility at 1877 Air Lane Drive in Nashville, Tennessee. This video provides a tour of the new facilities and talks about the work that goes on there. There is also a new look to our company website; it's been re-designed to make it even easier to use.


Near the intersection of I-40 and Briley Parkway in Nashville, you’ll find the offices of Interstate AC Service at  1877 Air Lane Drive.  This building has been home to our facility since Interstate AC Service was founded in 2004, but has undergone transformations over the years.  When we moved into this building 13 years ago, we shared it with an ambulance company, but by 2015, the ambulance company moved out, and the rapid growth of Interstate AC Service meant more space was needed. The old building was completely renovated and expanded.  The building is two-stories high in back and one-story in front.  We expanded the parking area for our trucks and staff, and provided an improved working environment for our employees. Walking through the glass enclosed entryway, you are now in the reception area with a corridor leading to a large conference room. On the way to the conference room, you pass by the break room. The corridor walls are decorated with beautiful Nashville scenes... very appropriate as we are a Nashville-based company! This one shows the Legislative Plaza, War Memorial Auditorium and State Capital building. Catherine Taylor, our Controller, admires this photo of Nashville’s Parthenon. In this corridor are photos of the old train station which is now the Union Station Hotel.  Tommy Gentry is a Service Specialist with many years’ experience designing residential HVAC systems and providing cost estimates.  The group of offices by the wall are for our commercial sales experts.

The nerve center of our new offices is this room dedicated to our dispatch staff. Our dispatchers are the first people our customers talk to and we value the trust you put in us.  Tony Anderson is one of the founders of Interstate AC Service, and he engineered the renovation of the new facilities. This corner office is occupied by Swaney Powers. He is in charge of our repair and installation work force. Every Monday morning, all our technicians arrive in their trucks to have parts and refrigerants replenished, engine oil changed, and any necessary truck maintenance. While that is going on, Swaney meets with the technicians, discusses process improvement, and helps resolve problems. On the second level, you’ll find the accounting area.  They keep the books, prepare invoices, and make payments. Catherine Taylor keeps this area of our business running smoothly. The commercial group is also on this floor and has space to spread out the large drawings required for retail and office building projects. Out in the yard is warehouse space and lots of parking. Our digital sign towers above the yard and is visible to drivers on I-40 heading west.  It can display a variety of messages.

A New Look to our Website, too! 

To go along with our new offices, we also have a new look to our website.  We’ve made it easier for mobile users, reduced the number of tabs, and the amount of text. Our HVAC News column contains over 118 information-rich posts, which include more than 45 videos, dealing with many aspects of HVAC.  Looking for tips to save money? Fixes you can do yourself? The latest in HVAC technology? Chances are, we have a post for whatever you’re looking for… and if not, let us know and we’ll write one!  Our website is visited by thousands of users from all over the world each month. We are proud to help educate HVAC owners and share our expertise with you.  Sign up as a subscriber and have the HVAC News delivered direct to your inbox. 


Thank you, Nashville, for letting us serve you.  1877 Air Lane Drive is the only place we’ve called home, but it feels even more so now.  We look forward to continuing to serve Nashville and the surrounding area, helping you with all your heating and air-conditioning needs.


Posted on 05/01/2017 6:03 AM by Eddie Hutton
Saturday, 15 April 2017

Storm, lightning, weather, HVAC damage, protectionpodcast, listen, audio, storm damageIn Middle Tennessee, destructive storms are not only the norm, but becoming more frequent.  Tennessee has already had more tornadoes so far this year than all of last year or the year before!  Your HVAC system is the single most costly system in your home – not just in yearly maintenance and energy costs, but also when it comes to replacing it.  Although you cannot prevent tornadoes, snow/ice storms, wind, hail, rain, lightening, and floods, you can help prevent some of the associated HVAC-related repair or replacement costs by taking a few precautions.  This post will provide useful tips for protecting your HVAC before and during a storm, as well as tips for dealing with some common problems after the storm has passed.

Before the Storm

In the spring (before “tornado season”) and in the fall (before snow and ice hit), go through this checklist:

HVAC placement, concrete pad, anchor, level, drainage, stormAnchor the outdoor unit. Your outside AC equipment should be installed on a level, raised, pad.  Ensure water does not pool near the unit during a heavy rain by ensuring downspouts are routed far away from the unit, that there is an adequate gravel border around the pad, and the land is sloped for optimal drainage.  

storm damage, projectiles, lawn furnitureRemove projectiles.  In Nashville, it is not uncommon to find your neighbor’s lawn furniture blown into your yard after a storm, or to have tree limbs fall on your property.  Secure or store any loose items from your yard such as lawn furniture or grills that can be blown into the outdoor unit. Remove or trim all bushes, trees and dead branches that could fall onto the unit in a storm.

hail guard, storm protection, HVAC precautions, hailInstall hail guards.  It has become commonplace for Tennessee to get hail along with rain and winds. Impacts from hail can be particularly damaging to the fins and refrigerant coil of the condensing unit.  Hail guards are thick metal “netting” that can stay in place year-round and still allow operation of the system (unlike covers!). They can be installed with hinges so they can be easily removed for servicing the unit. 

pipe insulation, foam insulation, electricalPrevent electrical shorts.  Be sure to cover and secure any wires between the outdoor unit and the house so that they are not exposed.  If they get wet or frayed, they could short out!  Over time, even insulated wires can deteriorate by normal sun and temperature changes.  Styrofoam “noodles” with hollowed out centers for wrapping around wires) are one way to keep the wires protected, and they can easily be cut to any length and taped shut with weather-proof tape.

Install surge suppression.  Storms often cause electrical disturbances or fluctuations in power (so-called “surges”).  To protect your HVAC equipment, install a high-quality surge protector that will automatically turn off your HVAC system to protect it from damage if there’s a spike in the line voltage. Consult an electrician to install a surge protector at the circuit breaker box. This can prevent expensive repairs due to blown fuses, burnt capacitors, and fried compressors.

Install a sump pump, if necessary.  Basement floods are a major cause of HVAC system problems. Protect your equipment by installing a sump pump to automatically detect and remove water. Consult a water-proofing professional to address your foundation and basement issues.  Keeping the basement and crawlspaces dry will also prevent mold from being drawn into the ductwork.

During a Storm

With all the weather alerts provided by various media – on TV, on our phones, and audible sirens – we often have at least a few minutes advance notice of impending destructive weather.  First and foremost, you need to seek shelter, but if time allows here are some steps you can take to prevent HVAC equipment damage:

  • breaker box, electrical, storm preparation, turn HVAC offTurn it off.  Avoid using your HVAC during a storm. Power surges might cause damage to its electronics. Shut off your heating and cooling system at the thermostat first, then at the circuit breaker. This ensures your AC or furnace will not inadvertently turn on during a storm, possibly damaging the coils or fins.
  • AC cover, compressor, outdoor unit, hail protection, HVAC coverCover it.  Most outdoor condensing units are not sheltered from the weather. Air conditioner covers (usually made of heavy canvas or vinyl) are relatively cheap, available online, and offer good protection from hail storms and snow and ice.  However, the system must remain off while it is covered.  Prior to turning your equipment back on after the storm, you must remember to remove the cover and any debris that has gathered on or around it.  Tip:  Do not use a tarp or other protective cover that completely covers the unit, as it can cause moisture to build up inside the unit or attract animals seeking shelter.  Leave at least a foot of space around the bottom of the unit to allow it to breathe.

After the Storm has Passed

HVAC damage, fins, hail, storm damageAfter the storm has passed, do not immediately switch the HVAC unit back on!  First, inspect your outdoor condensing unit for any signs of damage.  Look for cracks, impacts from hail or flying debris, harm to any of the refrigerant or electrical lines, and remove any debris that has fallen in or around the unit.  Check if there has been any movement or shifting of the unit off the pad, or if flooding and erosion has now caused the system to be un-level.  If you see any of this, call a licensed professional to inspect your system before turning it back on. If any power lines have fallen nearby your unit, do not approach the HVAC unit or turn it on until they are cleared.

But, What if…?

The more typical scenario is that the storm caused a power outage, and when the power was restored, the HVAC did not come back on as expected.  If this is the case, then after visually inspecting the inside and outside units and seeing no damage, follow these steps:

  1. Check the thermostat, to be sure it has power. Turn the thermostat off and then back on, wait a couple of minutes, then change the temperature to a setting that would normally trigger the unit to come on, and give it a few minutes to cycle.  If the unit still does not come on, then turn it off at the thermostat and proceed with step 2.
  2. Check the circuit breaker.  If it has been tripped, flip it off, wait a minute, and flip it back on again.  Then re-try step 1.  If the unit comes on for a short period and then goes off again, or if the circuit breaker is immediately tripped again, proceed to step 3.
  3. Call an HVAC service professional.  If there is evidence of a melted or burned fuse at the fuse box, contact a licensed electrical professional.  In either case, leave the unit turned off until help arrives.

electrical damage, lightning, electrical short, storm damageIn the event there has been visible damage or the unit has been hit by lightning, make photos of the damaged unit for your insurance company. Most insurance policies cover power surge damage to HVAC units and their associated electronics (thermostat, etc.).  Also, if there is any question, contact an HVAC professional so that something small does not turn into a major expense.  For example, replacing a damaged capacitor is an inexpensive repair but if it is ignored, it can lead to a failed compressor which is an extremely costly replacement.


Whether you need help preparing for a storm or dealing with its aftermath, know you can rely on Interstate AC Service to find the most affordable, effective way to deal with the problem.  If you live in the Nashville or surrounding area, call on us at (615) 832-8500.


Posted on 04/15/2017 2:00 PM by Tony Anderson
Friday, 31 March 2017

PodcastWith heating and cooling accounting for roughly 50% of your home’s energy consumption, things that decrease your monthly energy costs or help your HVAC to be more efficient are the best investments you can make.  Here are the 5 best ways to optimize your HVAC investment:

1.  Adding Attic Insulation

attic, insulation, investmentClose to 30% of your energy costs are due to heated air rising and escaping out the attic (during cold weather), and warm air coming in causing your air-conditioning to work harder (during warm weather). Laying insulation is an easy DIY project which can be done in a weekend with fairly inexpensive materials. It is the one most cost-effective thing you can do to improve comfort and lower your bills year-round. Tip: When laying insulation, don’t forget the attic access door, including weather stripping!

2.  Upgrade Your Thermostat

thermostat, temperature, Nest, Smart thermostatUsing a programmable thermostat is one of the best investments you can make to your HVAC system. By automatically setting the temperature down a few degrees when you are away and while you are sleeping, you could save up to 10% per year on energy costs year round, without sacrificing comfort. Upgrading your thermostat can be a DIY project, with companies like Honeywell and Nest offering installation tutorials on their websites, and it takes only minutes. Some new thermostats can be controlled using a smartphone or voice control, and can learn your habits or sense when you’re home, and adjust the temperature accordingly. Tip: Check out our posts on the new crop of thermostats here: Smart Thermostat Comparisons, Giving Away Smart Thermostats, Honeywell Wi-Fi Thermostat Case Study, Smart Thermostats, and Results of Our Smart Thermostat Poll. Let us know if you need help installing one!

3.  Get Your HVAC Serviced

HVAC service, maintenance, fall, spring, tune-upMoney Magazine states that regular HVAC system maintenance is one of the best investments you can make.  A professional inspection twice per year can find and fix minor problems before they turn into major ones, and makes sure your system is tuned up to operate most efficiently. Get your system checked before air-conditioning season in the spring, and before heating season in the fall. The bottom line is that regular HVAC maintenance saves you money!  Tip: The easiest thing you can do to help maintain your system is to change out the filters on a regular basis. See our posts: Air Filter Fundamentals, Selecting an Air Filter, Are More Expensive Air Filters Better?

4.  Replace Your HVAC System

Replace HVAC, Upgrade HVAC, R22 refrigerant, valueIf your system is more than 10-12 years old or has become a maintenance hog, you’re best served by investing in a new HVAC system. Since the R-22 refrigerant used by older systems has become increasingly expensive and scarce, an upgrade to a new unit that uses R-410A coolant makes sense. Plus, a new HVAC unit will offer greater efficiency, making your monthly bills much lower (see our post What’s Your SEER?). If you are buying or selling a house, there is no doubt that an up-to-date HVAC system is an attractive value – and an old HVAC system a significant deterrent. On the fence about replacing your system? See our posts Repair vs. Replacement, and Repair/Replacement – What’s the Real Question?

5.  Beyond the HVAC System

ceiling fan, HVAC value, temperatureSome of the best HVAC investments are things you can do which will lessen the need for your HVAC to work so hard.  Using ceiling fans will allow you to raise your thermostat 4 degrees without sacrificing comfort. Replacing windows with energy-efficient ones, and using caulk and weather stripping around windows and doors will save energy year-round. Replace your incandescent light bulbs with LED lights, which generate less heat. Use curtains or blinds inside and landscaping (trees) outside to lessen the amount of sunlight into the home, particularly on south-facing windows. This can save you up to 25% on summer energy costs. Despite what you may think, closing vents actually strains an HVAC system, resulting in more energy use, not less, so keep them open! Need to section off an area of your home? Consider zoning (see our post Is Zone Control for your HVAC the Answer?).


Let Interstate AC Service help you make wise investments when it comes to heating and air-conditioning. If you live in the Nashville or surrounding area, give us call at 615-832-8500.

Posted on 03/31/2017 10:13 PM by Tony Anderson
Wednesday, 01 March 2017

podcast, Zoning, Zone Control, HVAC Retrofit, Temperature controlDo you find the second level of your home stays too hot while the first floor stays too cold? Tired of fighting over the thermostat or lugging a space heater from room to room? Do the large windows or vaulted ceilings in your home cause pockets of hot and cold air?  It is not uncommon for even a well-maintained central HVAC system to have difficulty maintaining a comfortable, consistent temperature throughout a home. Zoning can solve a variety of these problems, plus offer up to 30% increased efficiencies, which translates into lower energy bills for you. A zoned HVAC system is a cost-effective alternative to having dual air systems (2 central HVAC units) that need separate furnaces and air conditioners for different areas of the home.Zone Control, HVAC systems, Temperature Control

Zoned systems have become very popular on new home construction, but they can also be added to existing homes. Just about any forced-air system can be retrofitted for zone control.  In this post, we’ll talk about what’s involved in retrofitting your single HVAC unit into multiple zones.

How Zoning Works

Zone control, HVAC zoning, duct dampers, thermostat, furnaceMultiple electronic thermostats – one in each zone - are wired to a control panel, or they may communicate with the control panel wirelessly.  Electronically-controlled dampers are installed in the ductwork and wired to the control panel.  Each thermostat continually reads the temperature in that zone and if it’s too low or too high, it sends a signal to the control panel to close or open the damper to that zone, thus regulating and controlling air flow to that  zone.

Saving Money

save money, green solution, HVAC efficiencyNot only is system zoning helpful for houses with inconsistent room temperatures, but it's also great for saving energy by not heating or cooling areas of the home where it’s not needed. According to the U.S. Department of Energy, system zoning can save homeowners up to 30 percent on a typical heating and cooling bill. Maybe you have a whole area of your house that is seldom used now that your son/daughter has gone off to college, so why pay to heat and cool it? Maybe you’re having to turn your current system way up just to keep the lower level warm enough, while the upper level is sweltering. System zoning allows you to save money by running temperature-controlled air to rooms only when it is necessary.

Planning the Zones

House zones, zone planning, HVAC zonesThe number of zones your home needs will affect the way you set up the system. In a two-zone system, with the zones being fairly equal in size, each zone's ductwork must be capable of handling up to 70 percent of the total CFM (cubic feet per minute) of air produced by your HVAC system. In a three-zone system, the zones need to be as close in total area as possible. In this case, each zone's ductwork should be able to handle up to 50 percent of the total CFM. Retrofitting more than 3 zones in a home may require ducts to be enlarged and/or to install a static pressure relief damper (also called a bypass damper), which will make retrofitting much more costly. So, when retrofitting, you’ll typically want to keep it to only 2 or 3 zones. Of course, if it’s a new install, the sky’s the limit, and it’s not unusual to have each room as a separate zone.

Not a DIY Project

not DIY, DIY not, Not do-it-yourselfAdding zoning to an existing HVAC system is not a DIY project, so you’ll want to consult an HVAC professional.  Depending on your duct layout, you may need to re-work the ducts to add a second zone.  But, before spending money on a zoning retrofit system, there are several things you can and should do which may help address many of these uneven heating and cooling issues, and may even eliminate the need for zoning.  We’ll talk about these in an upcoming post.


If you live in the Nashville or surrounding areas and have questions about whether zoning is an appropriate solution for you, give us a call at 615-832-8500. We’re here to answer your hardest questions and to help make your home a little more comfortable.

Posted on 03/01/2017 8:05 AM by Tony Anderson
Tuesday, 03 January 2017

The cold months of winter arrive this week. After the deep freeze we experienced last week, it looks like Middle Tennessee may be in for a challenging winter in 2017. During these long, cold winter months your furnace will work much harder and will require more energy than any other time of year. Fortunately, there are some steps you can take now to make your HVAC more energy efficient and save you money during the winter months!

1. Change the filter.

This is one of the easiest ways to make your furnace more energy efficient. If your filters are dirty the furnace will have to work harder to heat the home. Here's a helpful resource we put together for choosing the right air filter for your home. We recommend filters with MERV ratings between 8 and 11. They seem to be the most cost-effective.


2. Locate and take care of drafty areas in your home.

A good exercise is to get near a drafty area, close your eyes and imagine dollar bills leaving your home along with the heat. In our previous blog post, 4 THINGS YOU CAN DO NOW TO PREPARE FOR WINTER we took you through some of the most drafty areas of your home and provided some tips on sealing them to prepare your home for winter. Managing your drafts can result in energy savings during the winter months

3. Lower your thermostat while sleeping or away from home.

If you do not yet have a smart thermostat you will need to do this manually. There's really no need for your HVAC unit to work hard when everyone is sleeping or no one is home. The Department of Energy says You can save as much as 10% a year on heating and cooling by turning your thermostat back 7°-10°F for 8 hours a day- a normal workday!

There are further steps you can take to continue to reduce energy costs in your home but just starting with these 3 will get you off to a good start!

If you need help and live in the Nashville and surrounding area, please call on us at 615-832-8500. The professionals at Interstate AC Service are here for you.

Posted on 01/03/2017 2:19 PM by Tony Anderson
Tuesday, 13 December 2016

We hate to be the bearer of bad news (maybe good news to a few of you) but Winter just happens to be right around the corner. Yes, in this the year 2016, winter will come roaring in like a lion on December the 21st. Also known as 4 days before Christmas! We don't want you to be blindsided by this event, so today we're giving you 4 simple steps to take RIGHT NOW to prepare your home for the upcoming cold winter months.

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Step 1 Get your fall maintenance check up

The best defense against heating problems is to make sure your system is maintained year-round. Having heating equipment serviced before the heating season can reduce your heating bill and prevent repairs, breakdowns, and ensure your system is operating well.

Step 2 Prepare those hard to heat spaces

Our second recommendation for winterizing your home is to go ahead and prepare those hard-to-heat spaces! We all have that one or 2 rooms that just don't heat as well as the other rooms because of various reasons. For these spaces it's a good idea to go ahead and figure out how you're going to provide extra heating elements. Some options would be adding a furnace with blower or fireplace, inconspicuous baseboard heating or radiant floor heating. Read our complete guide here about heating local spaces.

Step 3 Preparing your windows, doors and other exterior structures.

Check for a good seal and weatherstripping. Problems with these can make doors and windows drafty and cause unnecessary heat loss. If you have storm doors and windows, the time to replace your current screens is now! Don't have storm windows? Try plastic wrap and weather tape to prevent drafts! Finally, check the wood around doors and windows for signs of rot or decay, cracks, gaps or broken glass and replace or repair if needed.

Step 4  Be sure overhead fans are rotating in the right direction.

Finally, make sure overhead fans are switched to the reverse or clockwise position, Doing this will blow warm air down to the floor leading to energy efficiency and comfort. This will in turn make room feel warmer, and you can lower the thermostat temperature! The only exception to this rule is if your ceiling fan is mounted on a two-story cathedral or a vaulted ceiling, the fan is too high to create this effect so it can stay in counterclockwise setting year round.

If you need help with winter preparation and live in the Nashville and surrounding area, please call on us at 615-832-8500. 

Posted on 12/13/2016 10:04 PM by Tony Anderson
Wednesday, 23 November 2016

There are many conflicting opinions online about getting your air ducts cleaned. In fact the EPA says there is currently no research on the benefits so they are careful not to make a recommendation either way. Since we are your resource for all things HVAC, we'd like to give you the honest facts- good, bad and ugly, that will hopefully help you make your difficult decision more easy.  

3 Good Reasons for Duct Cleaning

1. It never hurts to improve your air quality

petEverything in your home will get dirty. Homeowners regularly invest time and money in cleaning dust, dirt and other allergens from many surfaces of our home and removing toxins from our water system. In addition to normal dust and dirt accumulation, any of the following environmental factors will eventually affect your air quality:

  • pets
  • cigarette or cigar smoke
  • water contamination or damage to the home or HVAC system
  • home renovation or remodeling projects

2. Potential Energy savings

When your HVAC system is clean, it doesn't have to work as hard to maintain the desired temperature. As pollutants pile up in the system, it has to work much harder, using more energy and costing more to work properly. When your ducts are cleaned out, your HVAC unit uses less energy and leads to improved cost-effectiveness! 

3. Mold in these components could be making you sick

Contaminants and air pollutants, such as dander, dust, and chemicals are pulled into the HVAC system and re-circulated on average about 5 to 7 times per day. Over time, this recirculation will cause a buildup of these pollutants in the duct system. These pollutants affect the health of young children and the elderly more than anyone. This is why the National Air Duct Cleaners Association recommends homeowners clean their ducts once every three to five years. Furthermore, if you have allergies or asthma, autoimmune disorders or other respiratory health issues they recommend you consider having it done almost annually. 


The Bad and Ugly Side of Duct Cleaning

Duct cleaning is a costly and messy process. To do it right all of the components will need to be removed and everything will need to be cleaned. This includes the supply and return air ducts and registers, grilles and diffusers, heat exchangers heating and cooling coils, condensate drain pans (drip pans), fan motor and fan housing, and the air handling unit housing. This is a very time consuming and costly process. Just running a spinning polyester brush  through the ducts will leave 30% or more of the dirt in the ducts. 

If you choose to go ahead with duct cleaning, now may be a good time to schedule it. Right before winter is one of the best times to get your air ducts cleaned out as your ducts will be blowing the most air during the winter months. 

**Interstate AC Service does not  provide duct cleaning services.

f you live in the Nashville and surrounding area, please call on us at 615-832-8500. The professionals at Interstate AC Service are here for you.

Posted on 11/23/2016 10:01 AM by Tony Anderson
Saturday, 15 October 2016

You rely on your HVAC all year long. But now is when your HVAC is relying on YOU to take the necessary steps to keep it healthy all winter long. Here are six things you should do right now to prepare for the heating season ahead:

1. Change the air filters

The ones with MERV ratings between 8 and 11 are the most cost-effective (see our post Selecting an Air Filter). Not only will you boost your indoor air quality and reduce energy costs, but dirty air filters are the primary reason heating systems fail.

2. Clean-up

Keep your outdoor unit free of leaves, grass, and debris. Clean the coils with a garden hose (see our post The Low-down on Coil Cleaning). Make sure your indoor unit (furnace) is not covered with debris, too. Do not store anything flammable - paint, paint thinners, rags, glues, gasoline, cleaning solvents, and other chemicals - near your furnace. Keep at least 2-3 feet of clearance all the way around your indoor and outdoor units.

3. Address air flow issues

Make sure all the registers are open in all rooms, and that they are unblocked by furniture, drapes or debris (see our post on Vents, Registers & Grilles). Find and seal leaks everywhere throughout your home: leaks in your HVAC's ductwork, leaks around windows and doors (weather-stripping), around plumbing (caulking), and electrical outlets. Leaks especially in the ductwork as well as blocked vents make your HVAC work harder and could cause it to fail earlier. Plus, it wastes energy and money, and decreases your overall comfort.

4. Check the condensate drain line

Water that condenses during the operation of a heat pump or furnace is pumped into a drain line. Verify that the drain line is clear and that there is a clean reservoir in the pump. Bacteria and algae often block the condensate from draining, so clean it with bleach and add a few drops of an algaecide. Keep the drain line from freezing, too. If this drain gets backed up or frozen, your heat will shut down and could cause expensive repairs (see our post Fall Maintenance Secrets Condensate Drainage).

5. Time to switch

If you used a dehumidifier during the summer months, turn it off. If you have a humidifier, turn it on. If you don't have one, get one (see our posts Why Worry about Humidity in the Winter? and  Whole-house Humidifiers).

6. Get a fall maintenance check-up by an HVAC professional

Annual service is cheap compared to the cost of a breakdown. Both Money Magazine and Angie's List will tell you that getting regular HVAC maintenance tune-ups is one of the best ways to save money.  Plus, it could detect a potential health hazard, such as a carbon monoxide leak (see our posts Deadly Carbon Monoxide from Cracked Heat Exchangers  and Your Furnace Can Kill You!).

Doing just these 6 things in the fall will increase your HVAC's performance and efficiency, and help to prevent costly repairs.

For more tips on keeping your HVAC running smoothly, check out our website, podcasts, YouTube Channel, and download our Fall Maintenance eBook now. Here's to a fun and healthy fall!

Posted on 10/15/2016 11:38 PM by Tony Anderson
Saturday, 01 October 2016

In our last post, we talked about some of the things to consider when calculating the peak cooling capacity for an add-on space. In this post, we'll discuss some options for providing cooling to your add-on space.



Window air conditioner

This option is usually the first one homeowners dismiss, and with good reason. Although it may be cheap to install, it is very costly to run, unsightly especially if you can easily see it from the front of your house - and noisy. If you are cooling a basement space, you might not even have a window you can use! Assuming your add-on space is conducive to using a window air-conditioner, you're still left with a heating dilemma, and more than likely will need to use either a portable room heater or add-on baseboard heat (see our post "5 Ways to Heat Local Spaces").

Tying into your existing central HVAC system

Often, adding ductwork to your add-on space in order to connect it to your existing central HVAC system can be difficult or impossible, but this can be a great solution for providing both heat and air-conditioning. But, even if you can do it, doesn't mean you should. Here are some things to consider:

  • Is your current HVAC system rated to carry the additional load or will adding the additional space mean your existing system will now be under-sized, making your whole house uncomfortable?
  • Will the add-on space need to be a separate zone, so you can control the thermostat independently of the rest of the house? This is often the case when your add-on space is in an area with vastly different needs from the rest of the house: a room that is only used occasionally, a room that is underground, or has lots of windows (a sunroom), or a room with special equipment or machinery.

To see if tying into your current HVAC system is a viable option, you'll need to consult an HVAC professional.

Ductless Mini-Split an Ideal Solution

A ductless mini-split is often an ideal solution for most homeowners because it by-passes the expense of ductwork and is extremely efficient to install and operate. Mini-splits are available as air-conditioning only units, or as a heat pump offering both heating and cooling. Here are just some of the reasons why a mini-split might be a solution for your add-on space:

  • Ease of Installation: It only requires access to an electrical outlet and a single small hole in the wall (about 3" diameter, to accommodate refrigerant lines) for the indoor wall-mounted unit. The majority of the system sits outdoors.
  • Energy Efficiency: Because there is no loss of energy through ductwork (which accounts for up to 20% of the energy cost), these systems are exceedingly efficient. While your typical central HVAC systems may have SEER ratings of 13 or 14, a ductless mini-split offers SEER ratings of 20 or more (see our post What's Your SEER?).
  • Zoning: A mini-split is ideal for a room that is only used occasionally or is closed off part of the time: if no one is in the room, there is no reason to pay to heat or cool the space. It is also ideal for a room that will have vastly different heating or cooling requirements from the rest of your house, such as a sunroom or attic bonus room. A ductless mini-split can even be added to a room currently fed by your central HVAC system, but is hard to heat and cool compared with the rest of your house.
  • Features: Many of the latest crop of mini-split systems offer a multi-speed compressor, wireless remote control, programmable timer, and many other innovations.
  • Easy to Maintain: Most have washable, re-usable filters. Plus, it is much quieter than even the quietest window air-conditioner, and there are health benefits by not having ducts, which can gather dust, debris, and mold.

Posted on 10/01/2016 7:03 AM by Tony Anderson
Thursday, 15 September 2016

With real estate prices soaring in Nashville, many homeowners are opting to stay put and enhance their existing home rather than move. Perhaps you've decided to close in a garage to be used as living space, finish off a bonus room, add a sunroom, or turn basement storage into living space. Since these spaces were not part of your home's original central HVAC system, you're faced with a dilemma: what to do about heating and cooling these add-on spaces. In this post, we'll talk about some important considerations.

Location and configuration


Location and configuration of the add-on space matters when sizing the system.

basement remodel, add-on spaceCooling a basement which is partially or entirely underground will require less cooling capacity than cooling a room, such as a bonus room over the garage, which has a ceiling near the roof or attic, where heat tends to pool, and also has unconditioned space beneath it.

The number and type of windows and doors are also a consideratisuroom, add-on spaceon, as these are areas where cooling and heating energy is lost more rapidly.

​Does the add-on space get a lot of direct sun or is it protected by shade? Which direction does it face?  If you're enclosing a sunroom with large windows on many sides, it will require much more cooling than the other more traditional rooms of your house.

How high is the ceiling? Remember, you are cooling not just the square footage of the floor but the entire volume of the space.

Items such as this go into figuring the peak heating and cooling load for tAdd-on spacehe space.  Getting a system that is either too big (see our post "Think Bigger Is  Better? Not When it Comes to Cooling!") or too small can leave you feeling uncomfortable!  If you are in doubt about sizing an appropriate solution, you'll want to consult with an HVAC professional. No sense throwing money away on a system that won't do an adequate job.

How the space will be used

basement renovation, add-on space, remodelWill your add-on space be part of your regular day-to-day living space? Or will it be a room that might only be used occasionally, such as a guest room, or only used during certain seasons? Will the add-on space need to be a separate zone, so you can control the thermostat independently of the rest of the house?  This is often the case when your add-on space is in an area with vastly different needs from the rest of the house: a room that is underground (basement) or has lots of windows (a sunroom), or a room with special equipment or machinery. Will the room need just heating or just cooling or both? Knowing how the space will be used will aid you in selecting cooling and/or heating solutions that will be both functional and economical.

In our next post, we'll talk about the pros and cons of the various options for heating and cooling your add-on space.

Posted on 09/15/2016 7:17 AM by Tony Anderson
Thursday, 01 September 2016

Counterfeit RefrigerantsPodcast, audioCounterfeit and illegally imported refrigerants pose real safety and health concerns to HVAC technicians and consumers, as we detailed in our earlier post (see Beware of Fake Refrigerants!).  In recent years, with the curtailment of the refrigerant R-22 and its subsequent rise in price, this problem has gotten worse.  Now, there is much more scrutiny by the various authorities such as the EPA, IRS, and customs officials.

The Industry Fights Back

Dupont refrigerant, Hologram label, Anti-CounterfeitDupont hologram label, Izon Refrigerant, Anti-counterfeitThe HVAC industry now has much greater focus on recordkeeping and knowing the source of all supplies. To fight against counterfeit labeling, one refrigerant manufacturer has added a patented security hologram that provides immediate visual verification that the refrigerant is a genuine DuPont product.  The Izon® label is a unique 3D security system and contains an embedded code that allows for greater product tracking and traceability (see more info here).  Some refrigerant suppliers have begun routinely testing the contents of refrigerant cylinders they receive, using a halide test or a portable refrigerant analyzer, to spot contaminants and counterfeit products before they wind up in a consumer's system.

What You Can Do

Here are some things you do, to avoid becoming a victim of counterfeit refrigerants:

  1. Price CheckPrice: If the pricing you are quoted seems too good to be true, it probably is. The going price per pound for R-22 is about $45-95, and for R-410a it is $30-70. Know what you're getting and whether the price includes installation. Get quotes from multiple suppliers. If one seems crazy low, it could be it is an illegal import or counterfeit.

  1. Selling to Consumers: Although you can find cylinders of refrigerant selling online for much cheaper, it is illegal for a retailer to sell directly to consumers or to anyone who does not possess EPA 608 certification. If they will sell directly to you without this certification or do not ask to verify your certification, that is a big red flag!

  1. EPA 608 CertificationKnow your Supplier/Contractor: How long has your supplier or contractor been around? What is their reputation? Can you get in contact with them when you need to? Seek online or first-hand reviews from their customers. Verify that your HVAC technician carries Section 608 certification from the EPA. If they can't or won't show you proof of certification, that is a big red flag.

  1. Refrigerant cylindersVerify the Cylinder: Look closely at the labeling of the refrigerant your technician is using. Product names such as R-22a, 12a and 290 should not be used in a residential HVAC system. Verify that the technician is adding refrigerant from a cylinder that is clearly marked to be the "right" kind (if your system needs R-22 that it says R-22 on it) and has the manufacturer's name on it.

  1. Refrigerant LabelLabel Your Unit: Always insist your contractor/installer label your unit with the type of refrigerant they added. If they did use a legal R-22 substitute, such as R-422D, make sure it is labeled as such. That way, the next technician working on the system won't put R-22 in your now 422D unit. 

Important Tip
Filling Refrigerant, HVAC Service, Freon If you're having to add refrigerant to your system, it means you have a leak (see our post Fix the Refrigerant Leak Now!). If you have an older HVAC system that uses R-22, consult a reputable HVAC technician to see if it makes sense to continue investing in your existing system or if you'd be better off replacing it with a system that uses the more environmentally friendly R-410A refrigerant. Unfortunately, R-22 charged units are not compatible with R-410A refrigerant, so you'll have to replace the entire system (to help you weigh the pros and cons, see our post Repair or Replace?). On the bright side, if you do invest in a new unit, it will be more environmentally friendly and energy efficient, so you'll save money on your monthly cooling costs… and those long-term savings can really add up!

Posted on 09/01/2016 7:25 AM by Tony Anderson
Monday, 15 August 2016

Podcast, Fake Refrigerants, Listen



Fake Refrigerants, Counterfeit RefrigerantsCounterfeit and illegally imported refrigerants have existed in the HVAC industry for years. With R-22 increasing in price due to the government phase out (see previous post An Update on the Refrigerant R-22), people are doing anything they can to get their hands on cheaper solutions. Some refrigerants coming into the U.S. from other countries are not just imported illegally, but they are counterfeit, posing safety and health concerns to technicians and consumers. If you are having your air-conditioning system serviced, be alert to the various scams out there!

Unapproved Substitutes

EPA, Environmental Protection AgencySeveral companies have been penalized by the federal government for illegally marketing and selling other hydrocarbon products such as ES 22a as a replacement for R-22. (see  EPA vs EnviroSafe and EPA vs Northcutt).  According to the EPA,  use of ES 22a -  a refrigerant meant for window air conditioning units - creates the potential for explosion and fires, and is a serious risk to human health and the environment. R-22 air conditioners weren't built to handle the level of pressure or flammability these substitutes pose. In particular, R-22a, which uses propane, creates a fire hazard. Approved alternatives to R-22 do exist, such as R-422D, so check with your HVAC contractor.

Unapproved Additives

Duracool, R-22A, Additives, Fake RefrigerantsSome vendors have blended the refrigerant with flammable substances such as propane and butane, or with a pine-scented odorant (see R-22a Safety). These have been sold under the names OZ-12®, HC-12a®, and DURACOOL, to name a few. Use of flammable refrigerants as a retrofit in equipment that was designed for non-flammable materials presents risks to consumers, equipment, and service technicians, and will void your equipment's original manufacturer's warranty. There are stories where the compressor burst into flames, the technician sustained serious burns, and the siding was melted off the house!

Counterfeit Refrigerants

Counterfeit RefrigerantsSome counterfeit or contaminated refrigerants have counterfeit labels on the cylinders and packaging, so you can't tell what's actually inside. Contaminated refrigerants can cause a variety of issues, ranging from increased energy use and decreased cooling performance, to significantly reducing the operating life of your system, and causing injury and equipment failures.  Plus, many counterfeit  products contain ozone-depleting substances which are illegal. In China, 18 people were arrested from 4 criminal gangs, and 5 illegal production facilities were found, along with 11 storage warehouses and 2 sales offices. Over 28,000 canisters of fake R-134a and other refrigerants were confiscated along with 20 tons of raw materials (see report here).

Contaminated Refrigerants

Danger, Flammable, Contaminated Refrigerants, Methyl Chloride, R40Many refrigerants, including R-22, R-134a, R-404A, and R-410A, have been found to be badly contaminated (see report here). One of these contaminants is methyl chloride (also called R40 or chloromethane). It reacts with the aluminum and metal alloys used in the internal components of your HVAC system, causing corrosion and a volatile by-product that burns on contact with air. Exposure of the system's contents to air and/or moisture could result in production of a strong acid and violent chemical reaction. This contaminant was responsible for a fatal apartment fire in 2014.

In our next post, we'll tell you what the HVAC industry is doing to fight back and what you can do to avoid becoming a victim of fake refrigerants.

Posted on 08/15/2016 11:30 PM by Tony Anderson
Monday, 01 August 2016

Cleaning the air conditioner coils is part of regular spring and summer HVAC maintenance and is something homeowners can do themselves. Dirty coils can adversely affect your air conditioner's performance, and when the heat index creeps up past 100 as it has the past few days you need to get every bit of cooling you can from your air conditioning equipment! Any debris on the coils increases the static pressure across the coils and reduces your system's efficiency. Clean coils can boost your cooling capacity by up to 30%!

Symptoms of Dirty Coils

The coils are the part of your system where the actual transfer of heat occurs. Anything that insulates them will not only impact efficiency, but also will increase operating cost, and increase the likelihood of equipment failure. If you find your compressor keeps getting louder with each passing month, or that the compressor is overheating and turning itself off (leaving just the fan still running), cleaning the coils is a great place to start to remedy the situation.

Start With the Basics

  1. Check around your outdoor HVAC equipment and eliminate all obstructions within 3 feet all around the unit. That means trimming bushes, weeding, and removing all debris. Don't allow the lawn mower to discharge grass clippings onto the unit, or allow mulch or leaves to bury the bottom few inches, because it will restrict airflow, which will decrease efficiency and damage the unit.
  2. Check to see whether any of the fins have been damaged by mowing equipment, hail, or other calamity. Fins are the fine metallic blades that surround the condensing unit. If they have been bent, crushed or have rocks lodged in them, this will need to be remedied.
  3. Check to make sure the foundation upon which the outdoor unit sits is level. This is typically a concrete pad, but could also be plastic or rubber. Often, due to settling, erosion or drainage issues, these can crack, sink or become unlevel.  This puts strain on coolant lines, and could bend or break copper or electrical lines, or cause water to puddle in the unit. Make sure the pad raises the unit out of the dirt and that there is adequate drainage around it, so that water does not pool near it during a hard rain.
  4. Don't forget that you must turn the unit off before cleaning it. This doesn't mean simply that the unit is not running (e.g., set to a higher temperature), but rather the unit should be turned off at the switch usually a separate 240V power box near the unit - or at the circuit breaker box.

With these things addressed, you're ready to start cleaning the coils.

Coil Cleaners

Many manufacturers make coil cleaning products to aid in dislodging the contaminants on the coils. Some coil cleaners come in foaming aerosol cans, others are liquids or powders that must be mixed with water and used in a pump sprayer, still others are solvent sprays. Generally, these coil cleaning products are highly acidic or alkaline, and are harmful when inhaled or when they touch skin, causing irritation and in some cases burns. If you plan to use any of these coil cleaning products, be sure you are not downwind of the spray and that you are wearing gloves and eye protection. And here's a tip: if you're using them in a pump sprayer, this stuff can eat out the seals, so you'll need to use a special heavy-duty chemical-rated sprayer.

> > > Note: All types of coil cleaners are strong chemicals and must be handled with care. The manufacturer's directions should be read carefully and followed precisely to provide the best results.< < <

What About Detergents?

Many coil cleaners are referred to as "detergents," but do not confuse this with dishwashing detergents or laundry detergents! Never use those types of detergents on your HVAC equipment, as most have chemicals in them that are corrosive to metals. The aluminum, copper and metal alloys used in the manufacturing of fins and tubing, as well as the unit's plastic blower wheel and diaphragm (in the case of mini-split systems), are more sensitive and must be cleaned with a safe, non-acid cleaner.

Technique Matters!

Whether you're using a coil cleaner or not, you'll need a water source.  Never use a pressure washer!  Doing so could damage the coil fins and disperse chemicals into unwanted areas. Instead, use a standard garden hose. Begin by spraying the water from the inside of the unit outward, rather than from the outside inward, to prevent pushing debris further into the unit. Once you are certain all the debris has been dislodged, you can do final rinsing in all directions. In cases where there might be a thick film of dust, pollen, and grass clippings around the unit, a shop-vac can be used to remove such debris before washing the coils.

Our Recommendation

We recommend coil cleaner chemicals only if you have several layers of oily grime and only if they are used by a professional. Here's why: These cleaners, especially the foaming kind, can spread into hard-to-reach areas. If they are not completely rinsed out, they can corrode the metal and damage the unit. Coil cleaners are tough chemicals that can not only burn holes in your clothes (which is why you must wear protective equipment), but can damage paint. Consistent use of these cleaners over time can dissolve the outer metal and diminish the life of the coil, so we do not recommend them for routine maintenance. We recommend using just a garden hose and water.


After cleaning the external unit, and turning the A/C back on, you may notice that it is many times quieter than it was before. That's because the motor can work less and cool more efficiently. Few routine chores will pay off more handsomely, both in comfort and in dollars saved, than a simple coil cleaning. You'll also prolong the life of your air conditioner and have quieter operation. So what are waiting for?

Posted on 08/01/2016 6:57 AM by Tony Anderson
Friday, 15 July 2016

By mid-summer, you may begin to notice your air conditioner is not cooling as it should and may even be freezing up with visible ice forming on the lines or the condenser coil. This can be a sign there is a refrigerant leak. Perhaps additional refrigerant (a so-called "shot of Freon") was added at the beginning of the summer and you were hoping it would last the whole season. Now faced with a costly repair, such as replacement of an evaporator coil, you look for a way to postpone this major expenditure. Perhaps you've heard about various sealants and leak repair kits available online and in stores, often marketed as homeowner DIY projects, for about $150. Sound like a viable option? We'll explore the pros and cons.

What is a Leak Repair Kit?

Leak Repair Kits, Easy Seal, Super Seal, Leak FreezeOften sold under the trade name Leak Freeze, Easy Seal, or Super Seal, to name but a few, these leak repair kits are typically composed of: (1) a chemical liquid in a syringe or canister and (2) a short hose injector or applicator. Most of these products are meant to be injected into the refrigerant in your system.  The premise is that the chemical will travel throughout the system wherever the refrigerant goes and seek out the leak and form a seal at those points. But do they really work? How easy is it for a homeowner to use these kits effectively? By using them, can you avoid a professional AC service call?

Understanding the Fine Print

If you read the fine print and detailed instructions that come with many of these kits, they tell you some very important information.

  1. They won't fix very big leaks, only very small leaks. Do you know the size of your leak?  You can't always judge by how often you've needed to add refrigerant in the past, because several small leaks throughout the system can exhaust refrigerant at the same rate as one single larger leak.HVAC repair, Refrigerant service port
  2. They require your system be at a certain pressure to use (for example, 40-50 psi). Do you know your system's pressure? This often requires sophisticated equipment and gages, so you might need to contact a professional anyway. In fact, when you read the fine print, most leak repair kits will say they are designed to be used by HVAC professionals only. Indeed, the instructions can be a bit tricky for someone who doesn't know their way around a low side service port!
  3. Know what you're getting. Many leak repair kits are made for car AC repair. not home AC repair. Some are meant to be added to the oil in your system, not the refrigerant. Most will only in work in units of a certain size (for example, between 1.5-5 ton) and cannot be used in very small, very large, or commercial (non-residential) systems, though there may be other products for those types of systems.

Important Caveats

Besides the fine print, here are three things you should be aware of:

  1. HVAC Refrigerant, R22, Recharging air conditioner, shot of FreonAfter applying the sealant, you still need to refill the system with refrigerant. Thus, you can't get around another AC service call and the expense of "another shot of Freon" which can run you $400 or more!  As you know, the cost of the "old style" (R-22) refrigerant has increased greatly in recent years because it is being phased out by government regulations.
  2. Many leak repair kit manufacturers recommend applying a drying agent (such as Easy Dry) since the air that has gotten into your system from the leaks will cause corrosion. So, this additional step and cost must be considered.
  3. There is no guarantee how long the leak repair will last. If you have an older system with small pinhole leaks, and the product is successful at plugging them up, the chances are very great that new leaks will continue to form and that in a short time, you'll need to do everything again: spend money on another kit and recharging your system with more refrigerant making you wonder why you're spending all this money again and again for only a temporary fix!

Testimonials Tell the Story

Testimonials from Leak Repair Kit UsersThere is no doubt that you can find testimonials from people who have used these leak repair kits some even HVAC professionals - and they say they got another 5 years of use out of the system, so they were very happy with the results. But it seems there are just as many testimonials of people who have had disastrous results. Most scenarios go something like this: The leak repair seems to work initially and the system is able to hold the refrigerant charge. A few weeks later, the system freezes up and ceases working entirely. The homeowner finds out that the chemical in the leak repair kit caused a clog in the coil or compressor and that this has damaged the system beyond repair. What was once a costly part repair is now a major expense of replacing the entire HVAC system. The buyer has remorse for having wasted time and money.

Our Take on Leak Repair Kits

Using one of these leak repair kits is a poor substitute for having an experienced HVAC technician who will take the time to find out where the leak is coming from, determine how big it is and the cause, and provide a recommendation on how best to repair or replace the affected part(s). We definitely do not recommend trying to use a leak sealant on a newer unit (one less than 10 years old) because the risk of causing more damage is too great. For very old systems where you're facing a total replacement anyway, perhaps the risk is not as great. But because it's at best a temporary fix, the time and money you do spend is just postponing the inevitable.

Armed with the facts, you can now make a better decision. As we always say at Interstate AC Service "Knowledge is Power." For more information on refrigerant leaks, check out our other posts on this topic:

Posted on 07/15/2016 6:32 AM by Tony Anderson
Friday, 01 July 2016

Here at Interstate AC Service, we have a passion for green products and saving energy and thought you too would enjoy keeping abreast of the latest "green" gadgets. Water heaters account for 17% of your home's energy use, which is more than all other household appliances combined, so saving energy here can make a big impact on the environment and on your budget!


What is a Tankless Water Heater?

Tankless water heaters as the name implies, heat the water instantly as it's needed, without the use of a large "storage tank." By eliminating the need to keep a whole tank of water heated round-the-clock, just in case it's needed, you eliminate energy waste. You also reduce the air conditioning energy that is required to remove the waste heat around the water tank. A tankless water heater can be powered by electricity, natural gas, or propane, and can be 8-34% more efficient than traditional water heaters. Plus, because of their small size (about the size of a small suitcase), they can be installed anywhere, even a crawl space or attic.

Never Run Out of Hot Water Again

In many homes, running the dishwasher, laundry, and trying to take a shower at the same time is almost impossible without exhausting the capacity of the typical hot water storage tank. Tankless water heaters provide an "endless supply" of hot water because it is being made on-demand. When a hot water tap is turned on, cold water travels through a pipe into the unit. Either a gas burner or an electric element heats the water. As a result, tankless water heaters deliver a constant supply of hot water. You don't need to wait for a storage tank to fill up with enough hot water. A tankless water heater is best located near the place you want to use hot water, such as in the bathroom, kitchen, or laundry room. That way, little energy is lost getting the hot water to the point of use.


A tankless water heater's output limits the flow rate to 2 5 gallons per minute, with gas-fired tankless water heaters having higher flow rates than electric ones. In a large household, even the largest, gas-fired model cannot supply enough hot water for simultaneous, multiple uses in different areas of the house (for example, taking a shower and running the dishwasher simultaneously). There are two ways to deal with this: install two or more tankless water heaters in parallel, or install a separate tankless water heater near each appliance that uses hot water. Installing a separate tankless system near each appliance achieves the greatest efficiency (up to 50%).

Installation & Payback

Proper installation and maintenance of a tankless water heater will optimize its efficiency. The initial cost of a tankless water heater is more than a storage-type water heater, and you'll need the skills of a variety of tradespeople. Tankless water heaters require reconfiguring the existing water piping, installation of a new 120-volt electrical receptacle, and for gas-powered units, installation of a double-walled vent pipe through a side wall as well as a larger gas line. Thus, the installation costs are much greater: $2K-5K for a tankless (costs are dropping) vs $900-1300 for a traditional water heater. Plus, for tankless systems, yearly maintenance is required by a qualified technician, so that calcium build-up does not decrease the unit's efficiency.

ENERGY STAR® estimates that a typical family can save $100 or more per year with an ENERGY STAR qualified tankless water heater, depending on water usage and energy costs (gas or electric) in your area. And tankless water heaters have a much longer life - more than 20 years - compared to conventional water heaters, which typically last only 10-15 years. But, because of the higher purchase and installation costs, payback periods are generally on the order of 20 years or more for a tankless system.

Is a Tankless Right for You?

Studies reported that the majority of homeowners who switched to a tankless water heater were very happy with it. As long as you realize the upfront cost, you'll definitely save energy, and have unlimited hot water with a tankless unit. To help offset the upfront costs, there are some Federal Tax Credits (available until December 31, 2016 on gas-powered units only), and manufacturer's rebates offered. Plus, if you're going for LEED certification for your commercial or residential building, tankless water heaters may help you get there.

**Interstate AC Service is not a reseller or installer of tankless water heaters.

Posted on 07/01/2016 7:18 AM by Tony Anderson
Wednesday, 15 June 2016

Podcast, Listen, AC Myths, air-conditioningAir conditioning is a necessity in the south, especially as the temperatures soar into the 90's, and it is expensive! So we're here to debunk some air conditioning myths to help you stay cooler and save money this summer.

Myth 1:  Dropping the thermostat setting extra low will cool your house faster.

thermostat, cooling, myths, air-conditioningThis is generally not true. There are a few new variable speed air handlers on the market that can adjust their output to match demand. But most homes have a central air unit with just a single fan speed so it can only move warm air at a set speed. Your air conditioner will deliver cool air at the same rate no matter how low you go on the thermostat setting. If you turn the thermostat to 50 degrees when you want it to get to 72 degrees, your room won't get cooler any faster. By undercutting the desired temperature, you run the risk of wasting energy and money when you forget to set the thermostat back up.

Myth 2:  It's more efficient to leave your air conditioning running when you're not at home than it is to turn it off (raise the thermostat) and have to re-cool your house when you get home.

cooling efficiency, air-conditioning, energy use, AC mythWhile you're away, there's no need to keep replacing cool air with more cool air many times over. This just forces your A/C's compressor - the most energy-consuming element in your system - to operate constantly for the 8-10 hours you're gone. Turn your air conditioning down when you leave the house for extended periods and set a timer for about a half hour before you return home (here's where a programmable thermostat comes in handy!). During the cooling season, the longer your house stays at an increased temperature, the more energy and money you will save. One caveat: do not adjust the temperature more than 7-10 degrees. Otherwise, humidity can become a problem, especially within the walls and insulation.   

Myth 3:  Leaving a ceiling fan on will cool a room even if no one is in it.

ceiling fan, cooling, energy use, AC myths, air-conditioningFans cannot lower a room's air temperature. They create a cooling effect by causing evaporation on the skin. Fans cool people, not the air. Leaving your ceiling fan on when you're not in the room is a waste of energy and money. If you're in the room, however, you'll want to run the fan with the blades set to counter-clockwise, in order to create a downward breeze which will help you feel cooler. If a fan runs in a room when no one is there, no one is feeling its benefits. So it's just wasting energy. 

Myth 4:  Closing vents in unused rooms will boost efficiency.

vents, closed vent, air-conditioning, cooling efficiency, HVAC zonesThis only works if your home is already divided into separate HVAC zones, and you can control one zone independently of another. But most homes have the HVAC designed to distribute air throughout the entire house in a balanced fashion. If you close a register, the system keeps cooling and pumping without delivering the cool air to a usable space. You're basically paying to keep the inside of your ductwork cold! Worse yet, this may cause the compressor/condenser to cycle too frequently, and puts strain on the system, leading to accelerated wear and an early failure. Why risk this damage when it's not actually saving any energy?  If you only want to keep a single room cooler than the rest, consider a ductless mini-split air conditioner, or consider a zoned cooling system. A zoned system uses multiple thermostats that control dampers within the ductwork, allowing you to control room temperatures to suit your needs. Checkout our post about uneven heating and cooling for other possible culprits and solutions.

Myth 5:  Your air-conditioning unit will perform the same no matter where you install it.  

AC unit, installation, air-conditioning, AC myth, shadeInstallation is a key factor when it comes to efficiency. Try to install the outdoor unit in the shade or at least out of direct sunlight, on your home's north or east side, if possible. If you plant trees and shrubs around your unit for shade or simply for aesthetic reasons, make sure you don't block the airflow around the unit. When installing the thermostat inside your home, keep it away from heat sources, and away from lights and other appliances that give off heat, because it will make your unit run longer than it needs to. 


Cool Tip:  Any time you can turn a machine or light off, it will save energy. Lights are especially bad about heating up the air unless they are LEDs (check out our post "LED Lighting Lowers HVAC Costs"). You spend money to run the light and then have to spend more money on the air conditioning to counteract the heat it produces! So, when not in use, turn off the lights, appliances, and electronics.

Posted on 06/15/2016 3:16 PM by Eddie Hutton
Wednesday, 01 June 2016

Podcast, audio, mp3, Refrigerant LeaksPerhaps you've read or listened to one of our earlier posts entitled "Fix the Refrigerant Leak Now!" so you know how expensive refrigerant leaks can be! With the phasing out of R-22, a "shot of Freon" (as it is often called), could run you $400 or more. And there's no telling whether that will last a couple of months or a couple of weeks! Plus, it is detrimental to the environment, causing a depletion of ozone in our upper atmosphere. If you recharge the system several times, the oil in the compressor will deplete enough to damage the compressor, and then you may require a major and expensive repair! A properly-working air conditioner does not consume or use up refrigerant, so if it is running low on refrigerant, there is a leak somewhere in the system. But where? In this post, we'll talk about the most likely culprits.

Schrader Valve

The Schrader valve, also called the core valve, or service valve, is the port you hook up to when servicing the system. That's why finding a leak here can be so elusive: while it is in use, it doesn't leak. It's only when it is not engaged that the leak can be detected. Often, this can be as simple as putting a soapy solution around it and watch for bubbles to form, or using an electronic leak detector. The Schrader valve can become leaky when debris gets stuck in it, or when the rubber o-ring deteriorates. It used to be that to swap out the valve with a new one required removing all the existing refrigerant in the system (pumping it down) first. But now there are some specialized tools that allow you to swap out this valve while the system is still under pressure. After swapping it out, the system can be topped off with refrigerant. Consider yourself lucky if this is the problem because it is easily repaired.

Condenser Coil, Evaporator Coil, or Accumulator

The evaporator coil picks up heat from indoor air, and the condenser coil releases heat into outdoor air, so these coils are essential for heat exchange. Either or both can develop leaks over time. In some cases, you may be able to hear the hissing sound emanating from the coil and can determine where the leak is. What's more likely is that the coil has developed microscopic "pin holes" in several places. That's because these coils are typically made out of copper, which is particularly susceptible to pollutants such as formaldehyde which is often found in our homes in flooring, furniture, hairspray, and cleaners. Formaldehyde turns into formic acid which causes corrosion on the inside of the tubing. Ironically, newer systems that meet the government's mandate for increased efficiency may be more susceptible to these kinds of leaks. That's because A/C manufacturers found they can raise the efficiency of their equipment by using thinner copper in their evaporator coils, thus allowing faster heat transfer. Some A/C manufacturers have switched to aluminum coils to lessen the probability of this type of corrosion. Heat pumps typically have accumulators made of steel, which will rust over time.  Any of these types of causes are very expensive to address because they require replacement of the coil or accumulator which is a very expensive part, plus it requires a complete depressurizing of the system (withdrawing all refrigerant or "pumping down").

Joints, Seals, Lines and Tubing

Vibration of running the system, as well as environmental pollutants, can cause joints, rubber seals and copper tubing to weaken, split, separate, or rust. A lawn mower or nail may have punctured a line. Steel parts will rust if not galvanized or made rust-proof. Age is also a factor, because the system is under high pressure causing the walls of the tubing to thin and weaken over time. These leaks can be hard to find and may require disassembly of the unit. To locate the source of the leak may involve injecting a tracer (a fluorescent dye) into the system and then re-checking the system about 10 days later using a UV lamp to see where the dye has leaked out. Once the source is found, the joint, connection, or hole in the tube can be fixed by re-soldering, cutting it out, replacing it or by-passing it. The diagnosis and repair of these conditions can be time-consuming and thus expensive.

A Dilemma

Depending on the age of the air conditioner or heat pump, and the type of refrigerant it uses, you may be faced with a dilemma: You may need to consider replacing it rather than repairing it. Weighing the costs can be tricky, so you'll want to read our post entitled "Repair vs Replacement." Keep in mind it is possible to repair one refrigerant leak and have another one develop in a different location shortly thereafter. Whatever you decide, doing nothing is not an option. Sure, the cost to repair or replace your system may be higher than simply adding another "shot of Freon," but not repairing a leak causes recurring expenses that will only escalate, risks major damage to your system that could be even more costly, and injures the environment.

DIY? Not!

Finding the source of a refrigerant leak requires the use of specialized tools and supplies, specialized training, and is something few homeowners can do themselves.  Recharging the system with refrigerant whether the "old" R-22 or R-410A equivalent, or the new refrigerant R-422 is definitely not something a homeowner can do since it requires a government license to order and use these refrigerants. Depend on the experts at Interstate AC Service to diagnose the source of your leak, fix it, recharge your system, and get your air conditioner operating at peak efficiency.

Posted on 06/01/2016 6:05 AM by Tony Anderson
Sunday, 15 May 2016

It may surprise you to learn that indoor air pollution is among the top five environmental health risks. That's why we've been devoting a series of posts on air filtration.  If you've been watching and listening to our posts, you've heard us talk about the MERV ratings of air filters, and how to select the best air filter for your needs. As a general rule, prices are higher for filters with higher MERV ratings. But here is one instance when the buying the best, most expensive filters those with MERV ratings greater than 16 may do more harm than good.

HEPA Filters

Among the most expensive filters are HEPA filters. Higher efficiency filters with a MERV rating of 14 to 16, are sometimes misidentified as HEPA filters.  But true HEPA filters have MERV values of 17 to 20.  HEPA which stands for High-Efficiency Particulate Arrestance - is a special type of filter that, according to DOE standards, filters out 99.97% of particles down to 0.3 microns in size… that's 10 times smaller than a MERV 16 filter!  HEPA filters are typically used in biomedical applications to filter out bacteria and viruses. 

More Harm Than Good

True HEPA filters those with MERV ratings 17 and above - are normally not installed in residential HVAC systems. A typical residential air handling unit and associated ductwork cannot accommodate HEPA filters. They do not have enough fan or motor capacity to accommodate the large pressure drop across the dense HEPA filter material. If you install a HEPA filter in an HVAC system not specifically designed for it, it will make your motor work harder because it is getting too much resistance, and this will hamper your airflow, increase fan noise, and cause your system to fail earlier. Check with your HVAC manufacturer prior to upgrading filters to determine whether it is feasible to use more efficient filters.

Let's Get Real

According to the EPA, using medium-efficiency filters, such as those with a MERV rating of 12-13, are almost as effective as true HEPA filters at removing allergens, with much lower associated system and operating costs, and quieter fan operation.  Furthermore, many air particles never go through your HVAC filter system because they are deposited in your living space on your sheets, furniture, and carpet, for example.  So, you still need to change your sheets, vacuum, and do all those house-cleaning chores regularly to maintain your indoor air quality.

Things You Can Do

Here are some other simple things you can do to improve your indoor air quality:

  • Prevent mold by controlling moisture throughout your home.  That means turning on exhaust fans in bathrooms while showering, and making sure your basement and crawlspaces are dry.
  • Fix any leaks in your ductwork, in the roof, around windows and doors, and around plumbing fixtures.
  • Keep your home smoke-free. Do not smoke indoors, don't burn candles and incense, and use exhaust fans while cooking.

Posted on 05/15/2016 5:07 AM by Tony Anderson
Sunday, 01 May 2016











Over the years, we've posted lots of great tips and answers to customers' questions on our HVAC News page and podcasts. Now we've compiled and edited all the posts dealing with spring maintenance (getting ready for air-conditioning season) into a single resource. We've included links to the videos and podcasts that first appeared with these articles. Download the PDF now. Our free gift to you to celebrate our 100th post since first post August 1, 2012.  Enjoy!

Posted on 05/01/2016 7:02 AM by Tony Anderson
Friday, 15 April 2016

When you go to a hardware or big box store to purchase air filters you will find a bewildering array of products. 3M, for example, offers 9 different types of filters each with different ratings and at a different price, and then each of those comes in different sizes. It can be confusing, to say the least!  We'll help you make sense of it all, so you can choose the best air filter for your needs.

Size Matters

Size is perhaps the easiest decision: get the size filter that fits the filter holder built into your HVAC system. It should fit snugly, with no air gaps around the filter. Be aware that filters come in thicknesses of 1-inch to 6- inches, with the thicker filters having greater capacity to catch dirt without increasing resistance to air flow and increasing the time between required filter changes.  However, you cannot put a thick filter (4 or 6 inches thick) into your HVAC system if it's designed to accommodate only a 1-inch thick filter.

Rating Matters

In our previous post, we talked about the MERV ratings of filters.  MERV is an industry standard measurement of filter efficiency.  Individual manufacturers often have their own rating system as well.  3M's rating is called MPR, which standard for Microparticle Performance Rating.  As with the MERV rating, higher MPR numbers mean a greater percentage of particles and smaller particle sizes will be captured by the filter.  

Price vs Performance

How do you decide which MERV rating to get?  Generally, the higher the MERV (or MPR) rating, the more expensive the filter.  For example, the price of a MERV 13 filter is about twice the price of a MERV 8 filter of the same size. 3M offers multiple filters having a MERV 12 rating, but with different MPR ratings, and so even among filters of the same size and MERV rating, the prices can vary.  Which filter to buy depends on how much cleaning you want your filter to do. The lowest price filters at MERV 5 will remove dust, debris and lint. This is the minimum needed to maintain the health of your HVAC system's heat exchanger and coils.  A MERV 11 filter removes smaller particles such as pollen, dust mites, mold spores, and pet dander. A MERV 12 or 13 filter can filter some bacteria, viruses, and odors.  Since the prices jump up dramatically at MERV ratings higher than 11, and the increased efficiency is only minimally incremental, using filters with more than a MERV 11 rating is probably not cost effective, unless there is some particular medical need.  In the chart, those shown in the "green zone" in the cost column represent the best value on a price vs. performance scale.



Posted on 04/15/2016 7:50 AM by Tony Anderson
Friday, 01 April 2016

Podcast, Air Filter, ListenYou've heard us preach over and over about how important it is to change your air filters on a regular basis. But there are so many to choose from these days and prices vary widely!  We'll help you make sense of it all in this and two subsequent posts on this subject.

What's the purpose?

Furnace filter, Air Filter, Duct filter, HVACThe purpose of an air filter is to keep the coils and heat exchanger inside your HVAC system clean. Dirty coils and heat exchangers can make the system work harder and cause it to be replaced earlier, so keeping the filter clean helps prolong the life of your HVAC system. Since the air in your house circulates past these filters, they also affect the quality of the air you breathe. People with allergies or asthma are especially sensitive to airborne particles like pet dander, pollen, mold and dust, and the right filter will filter out these particles.

What is a MERV rating?

Air Filters, Filtrete, MervWhen it comes to air filters, the most important thing to look for - besides the correct size for your particular system - is the MERV rating. MERV stands for Minimum Efficiency Reporting Value. It is a measurement standard designed in 1987 by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) to rate the effectiveness of air filters. The MERV rating is a number from 0 to 20, with most residential air filters in the 4-12 range. The higher the MERV rating, the more efficient the filter is, and the greater percentage of particles it can capture. MERV is an industry standard rating, so it can be used to compare filters made by different companies.

As a general rule, prices are higher for filters with higher MERV ratings. Often HEPA filters are rated in the range of MERV 17 to 20, and are the most expensive types of filters. But here is one instance when the most expensive may not be the best!  Most residential HVAC systems may not have enough fan or motor capacity to accommodate higher efficiency filters, such as those greater than MERV 16. Always check your HVAC manufacturer's recommendations.

Installation Affects Performance

How a filter is installed also effects its performance. If a filter is installed such that air bypasses the filter, its effectiveness will go down substantially, so make sure the filter is the right size and it's a snug fit. Plus, most filters are directional, meaning you have to install them facing the right direction. Check for the arrow which indicates the direction of air flow, and install the filter with the arrow pointing towards the duct. Here's another tip: If you have your HVAC system's fan set to "auto" then the air is only going past the filter when your system kicks on. By setting it to "on" the fan will continually move air across the filter, so the air you breathe will be continually filtered.

Most Important Thing

Date Filter, Filter Installation, Air FilterThe most important thing to remember about home air filters is to change them regularly. Even the highest-quality filter won't work if it is clogged with particles!  Check the filter manufacturer's guidelines, as different filters are meant to be changed at different intervals. Plus, if you're doing remodeling, there is construction going on, or you have pets, you will need to change your filters more frequently to compensate for the extra dust and residue in the air. Mark the date of installation along the filter's frame, so you can clearly see when it was last changed.

Posted on 04/01/2016 7:02 AM by Tony Anderson
Tuesday, 15 March 2016

listen, Podcast, electronic air filter, electronic air cleanerNashville is known for its great music, hot chicken, and unfortunately, its sometimes poor air quality… largely due to ozone, pollens and particulates. Things linger in our air because middle TN sits in a "bowl" surrounded by mountain ridges and vegetation the natural wonders that give this area its beauty.  People who are allergy-sensitive know all too well that springtime is approaching!  Of course, you should be changing your air filters on a regular basis at least every 3 months. But, did you know there is more you can do to help the air quality in your home?  Consider installing a whole-house electronic air cleaner.

Honeywell Electrostatic Air Cleaner

What is an Electronic Air Cleaner?

Electronic Air Cleaner DiagramThis is a device that attaches directly into the HVAC ductwork feeding your whole house. As the name implies, this is an electronic filter not just some folded mesh encased in a cardboard frame like a typical air filter. It works by placing a negative electric charge on airborne particles and a positive electric charge on the media and, because opposites attract, it collects airborne particles like a magnet. To give you some perspective, typical air filters remove particles down to about 750-1000 microns in size, or about the size of the eye of a sewing needle. But, an electronic air cleaner can remove particles less than 10 microns in size a size so small it would require an electron microscope to see!  Particles of this small size stay suspended in air easily and account for 99% of the total number of particles in unfiltered air.

Low Maintenance

Cleaning the Electronic Air FilterBesides dramatically increasing your air quality, electronic air cleaners are low maintenance and economical. They can be easily removed from the ductwork, washed in your dishwasher or sink, drip dried, and re-installed. They do not have to be replaced every 3 months like typical air filters. Some systems offer an integrated LCD display or fault light to remind you when the filter needs cleaning. Runtime on these filters is not based on calendar days, but on the length of time your HVAC system runs. It is recommended that you leave your HVAC system's fan set to "on" rather than "auto" for maximum air cleaning benefit. Most electronic air cleaners come with a 10-year warranty and use about as much electricity as a 40-watt light bulb.  

Often Confused with Electrostatic Filters

Do not confuse electronic air cleaners with electrostatic air filters! Electrostatic filters have a charge applied to them at the factory which is supposed to last the life of the filter, but their efficiency is poor at best and degrades over time. Electronic air filters are made using either precipitator or polarized media technologies, both of which require a power supply. Electronic air cleaners have a continuous charge applied making them very efficient dust magnets!

Other Benefits

Electrostatic Air Cleaner DuctworkIn a previous post, we talked about duct cleaning. But, if you have an electronic air filter and well-sealed ducts, you should never need your ducts cleaned, as particles won't ever get the chance to deposit themselves in the ducts or build up over time. Additionally, your HVAC system's blower, air conditioning coils, and heat exchanger will be protected from particles and so will last longer and be more efficient. In fact, one electronic air cleaner manufacturer guarantees that if your indoor coil requires cleaning within 10 years of  installing their electronic air cleaner, they will pay to have it cleaned!


Don't Forget This

Whether you have a whole-house electronic air filter or not, you still need to change your air filters in your return air vents every three months!


Posted on 03/15/2016 7:55 AM by Eddie Hutton
Tuesday, 01 March 2016

Depending who you ask, folks will either tell you that cleaning your ducts is a must or it's just a waste of money.  Who can you believe?  We're here to help you make sense of this difficult question. First, let's clarify what we mean when we say ducts.  In one of our earlier posts, we talked about the duct opening, called the register or vent.  We described how you can clean these yourself, by taking off the vent cover and using a small vacuum or cloth. But when we refer to duct cleaning, we're talking about the many yards of conduit or enclosed raceways that go between your HVAC system the heating and cooling source and the various room destinations the vent outlet.  Ducts are often hidden within walls, in attic or basement spaces, or in a crawl space. Duct cleaning requires specialized equipment and must be done by a professional… it is not a DIY project.

A Scam?

Duct cleaning is never recommended as routine periodic maintenance. According to the Environmental Protection Agency (the EPA), there is no scientific evidence that regular residential air duct cleaning improves air quality.  Checking and changing your system's filters on a regular basis, keeping your system well maintained, having regular inspections, and ensuring moisture doesn't get in are some of the most important things you can do to maintain good air quality and keep your ducts clean. 

A Symptom, Not the Problem

Dirty ducts are often merely a symptom and not the cause of the problem; thus, cleaning them does not eliminate the problem.  If you have mold, you have a moisture issue that needs to be addressed.  If you're not getting good air flow, there are many possible reasons, each of which should be explored.  Don't get talked into getting your ducts cleaned as a treatment for or prevention of allergies. Getting a good filter one that traps allergens - and changing it often is a simpler and more cost-effective solution. 

Benefits vs Risks

Just like when treating a medical condition, you must make sure the benefits are worth the risks.  Duct cleaning is a fragile operation, and can kick up particles or even cause your ducts to break. Duct cleaning services can run $600 a bit more or less, depending on the size of your house - and can take 3 hours or more.  Because ducts typically have bends, tape and screws, there are many places for dirt to get trapped and hide.  The only way to thoroughly clean ducts is to remove them and and clean the individual pieces. In that case, you may be better off just replacing the ducts. Eddie Hutton is one of our owners. Click video to see and hear how he sums it up.

If you're still on the fence about duct cleaning and live in the Nashville area, call and we'll be happy to come out and do an assessment.

**Interstate AC Service does not provide duct cleaning services.

Posted on 03/01/2016 6:17 AM by Eddie Hutton
Monday, 15 February 2016


Podcast, HVAC service technician, parts replacementAs much as we try to provide do-it-yourself tips, it's just a fact of life that sooner or later you'll be at the mercy of an HVAC professional.  After all, HVAC systems are complex equipment requiring in-depth knowledge of electricity, plumbing and mechanical systems, specialized diagnostic equipment, state licensure and EPA certification.  When it comes to HVAC trades people, there are basically two types: the "parts replacer" and the "service technician."

The Parts Replacer

HVAC parts, parts replacementThis individual knows how to replace parts, but may not have the necessary advanced trouble-shooting and engineering skills or may not want to put forth that extra time and effort that may be required for your situation.  Has this ever happened to you?  You spend money to replace a part, only to have similar trouble just a week or two later, so they come out and replace a different part.  This could be a sign that no in-depth trouble-shooting was done initially to determine the exact cause of the problem, and the technician merely replaced the "most likely" part hoping that might fix it.  The parts replacer mentality can be very costly for the consumer!  You wind up buying things you might not need, and the real preventive maintenance is not done on the system…because it is just easier to let it fail and replace it later.

Tip:  Any time a part is replaced, make sure you see the old part that is removed, and the new part being installed.  You may not have a clue about the parts themselves, but at least you'll be assured that if you paid for a new part to be swapped out with old part, that it actually was!  Then, hang on to the old part, and if it turned out not to be the problem after all, ask for it to be reinstalled and demand a refund for the cost of its wrongful replacement.

The Service Technician

HVAC service technician, Interstate AC ServiceThis individual takes the word "service" seriously.  They spend the time and effort necessary to investigate the problem and find the best solution… and they know the best solution is not always to replace parts.  This individual takes the word "technician" seriously, too.  They are not afraid to tackle a difficult repair or to fabricate a part or to engineer a more optimal solution.  They realize that there is more to being an HVAC service technician than simply being able to replace parts.  Listening to the customer and being sensitive to their needs is just as important as the technical skills they possess.  These types of people actually protect your investment in your HVAC system and save you money in the long-run by keeping your system tuned and by preventing the need for parts replacement.  Sure you can replace a failed part, but not fixing the underlying cause of what made that part fail in the first place means you'll be spending more later.  This is why the lowest bid on a job may not always be the one you should choose.

Tip:  Always seek out a second opinion if a major expense is proposed, and don't be quick to opt for the lowest price.  Ask questions about what will be done: what parts will be repaired or replaced and the amount of time it will take.  Ask also if they will guarantee their work.  If they hem and haw at your questions, that's not a good sign!

In short, a parts replacer is reactive, while a service technician is proactive. Service technicians will use their advanced technical knowledge and equipment to correctly diagnose the problem and repair it the first time.  While parts replacers keep swapping out parts hoping to stumble across the correct solution. Which type of HVAC professional do you want working on your systems? 

Posted on 02/15/2016 6:21 AM by Tony Anderson
Monday, 01 February 2016

Podcast, Heating Fixes, DIY, Listen, thermostat, furnace, filter, serviceIt always seems your heat will go out on the coldest day of the year!  Why spend money when you may be able to fix it yourself? Here are a few examples of do-it-yourself easy fixes:



Is the display on your thermostat blank? It could be because it needs a battery, or that the circuit breaker to it has been tripped or you've blown a fuse. Reset the tripped circuit breaker, replace the fuse, or replace the battery.  Other thermostat tips:

  • Make sure all the wires going to the thermostat are connected and not loose.
  • Check that the thermostat is in heat mode. This switch can easily get accidentally bumped while dusting.
  • For programmable thermostats, check that it is set to the correct day and time, including the AM or PM designation.  One customer bought a programmable thermostat to save money, with the intent to have the heat backed down while the customer was away at work, and have the heat cranked up at night when the customer was home.  When the customer started freezing at night, they mistakenly thought something was wrong with the heat, when the real culprit was they had the AM/PM designation backwards on their thermostat!
  • If you had a recent power outage, it could be that all of the settings on your programmable thermostat have been wiped out.  Often there is a battery backup in these units, so you may need to change the battery and then re-enter your settings.


If the heat is out and you do not even hear the fan coming on (no air coming out of the supply registers), there may be no power to the furnace.  This is often due to someone flipping the switch accidentally while cleaning out the attic or basement (areas where the furnace may reside). The switch often looks similar to a light switch and easy to mistakenly turn off.  Just flip the switch back, and you should hear the furnace start up within 3-5 minutes. Other furnace tips:

  • Many thermostats get their power from the same electrical circuit that feeds the furnace system, so if your thermostat is blank, turning on the switch by the furnace may be the solution.
  • If the fan runs, but the air coming out is cold, you have a problem with the furnace (or heat pump) itself, and may need a service call.
  • Some furnaces have emergency cut-off switches that are activated when a door or service panel is removed. If the furnace door is not closed properly (such as after a filter cleaning), or has been accidentally bumped open, the cut-off switch will prevent the furnace from coming on.  Verify all access doors are properly closed.


If the switch is on to the furnace and it still doesn't come on, it could be that the circuit breaker or fuse to the furnace (or heat pump) is tripped or blown.  Reset the breaker by turning it all the way OFF, then back ON. If the fuse for the furnace is blown, replace it with the same size and type of fuse.  Important electrical tip:

  • If a breaker keeps tripping or a fuse keeps blowing, contact a qualified electrician to inspect your system to determine why you are having problems.




A dirty air filter restricts air flow, and the system will work harder and build up pressure. Newer, more efficient furnaces are sensitive to this pressure build up and turn off before the dirty filter can cause further damage. At the very least, a dirty, clogged filter will reduce the heat output of your system. The simple solution is change the filter!   Important tip:

  • Don't try to just vacuum the existing filter and re-insert it. The material inside the filter will still be saturated. Just place the old filter in the trash and insert a new one each time… at least every 3 months.

If none of these DIY fixes addresses your problem, give us a call.  We're always here to help!    

Posted on 02/01/2016 7:03 AM by Tony Anderson
Friday, 15 January 2016

You may be familiar with a space or room humidifier, but did you know you can get a whole-house humidifier? This is a device that gets mounted to your furnace's hot air supply. Warm air is sucked into the humidifier, where it absorbs moisture. Then, the now moisture-rich air is passed back through the vents of your home.


Whole house humidifiers offer several advantages compared to room humidifiers:

Convenience: They condition the whole house evenly with a single unit, so you do not have to have space in every room to plug in and setup a separate room humidifier. Plus, furnace humidifiers are typically plumbed directly to a water line, so there is no need to constantly clean and refill a water reservoir, as is required with a room humidifier.

Maintenance: Maintenance is easy with a furnace humidifier: just have it checked and filter changed once at the start of each heating season.

Safety:  Because there is fresh water plumbed into a furnace humidifier, water doesn't sit around to accumulate mold.  Also, with room humidifiers, there is always the danger of someone tipping the unit over and splashing water everywhere.

Control:  A furnace humidifier can be controlled by a humidistat, which is a device similar to a thermostat that allows you to adjust or set the desired humidity output. This is a great way to avoid air that is too dry or too moist with a simple dial, panel or switch. Some units actually replace your existing house thermostat with a single, integrated humidistat/thermostat.

Types of Whole House Humidifiers

There are many types of whole-house humidifiers:

  • Fan-powered humidifier units have their own fans separate from your heating unit's fan - that add moisture directly into your ducts.
  • By-pass humidifiers, on the other hand, work with your furnace's existing system to deliver enhanced moisture throughout your home.
  • Flow-through humidifiers are the most common, and operate by sending water directly through the unit to add moisture to the warmed air.
  • A reservoir humidifier uses an actual reservoir of water that then gets gradually funneled into the air to reach the ideal level of humidity. There is a filter that water flows through and your furnace's warm air blows through the filter.
  • A steam humidifier, as the name suggests, incorporates steam into the air that is evaporated from water. It is the most expensive type of humidifier, but also the most effective and allows more precise control of the humidity. They come in cold and hot water forms, injecting hot or cold steam into your supply line.

Important Tip: If you have two HVAC units in your house one upstairs and one downstairs you only need a single furnace humidifier on your downstairs unit, since humidity rises.


Costs for a furnace humidifier range from $350-$500 including installation.  Although some are marketed as do-it-yourself, we recommend calling a professional, since a water line and electrical line may need to be run for the humidistat and fan. Call Interstate AC Service for help at 615-832-8500.

Posted on 01/15/2016 1:14 AM by Tony Anderson
Saturday, 02 January 2016

Winter is the time to worry about a lack of humidity in your home. This post explains how proper humidity levels improve your health and the health of pets, plants, and furniture, eliminates static shock, and decreases your heating bill.


In Middle Tennessee, we are all too familiar with the long, humid summers. But in the winter, the humidity is very low, and when indoors in heated space it's even lower, so that should be a good thing, right?  Not so!  If your indoor humidity is below 30%, you could actually be causing harm to yourself and your home, and increasing your energy bills while decreasing your comfort.

Humidity Affects Your Health

Low humidity can adversely affect your health. It can make your throat feel dry, aggravate respiratory ailments, increase respiratory infections including colds and flu, cause itchy, dry skin and even nosebleeds. Many doctors recommend whole-house humidification for allergy and asthma sufferers.

Humidity Affects Your House

Dry air can adversely affect other things in your home, too. It steals moisture from your plants, your pets, your furniture and all the wood in your home. Hardwood floors separate at the seams, furniture shrinks and cracks, doors warp and no longer fit their frames, wallpaper and paint crack and peel. 

Humidity Affects Electronics

Perhaps one of the most annoying effects of dry indoor air is static shock. Ever get "zapped" after walking across the carpet, or "zap" your pet or someone else? This static electricity can even wreak havoc on home computers and other sensitive electronic devices.

Proper Humidity Saves Energy

How does humidity save energy? Warm, humid summer air feels hotter than it actually is because of the moisture it contains. That same principle applies to your home in the winter. By keeping the relative humidity inside your home at an ideal level typically between 30-40% - you can turn your thermostat down a few degrees and actually feel more comfortable.

If you haven't already, subscribe to our podcasts or our HVAC News posts so you won't miss the next post in this series, where we talk about whole house humidifiers.

Posted on 01/02/2016 6:59 AM by Eddie Hutton
Tuesday, 15 December 2015

Podcast, Heating options, Listen

 For a few months of the year, heat is essential in Middle Tennessee. Although central heating systems (a gas furnace or electric heat pump) are common, suppose you only need to heat a certain room or area of the house? Perhaps you've re-purposed a previously unheated space such as a garage, or you closed off part of the house in the winter and so only require heating in a smaller area. Maybe you have one room in your house that is just never warm enough, despite having central heat.  Well, there are many local heating options that can address these issues.  Local or room heating uses a separate thermostat for each room or area, and thus allows you to take advantage of adjusting just that area to the temperature you want, rather than setting one temperature for the whole house as you would with a central heating system.  Here are 5 local heat options to consider:

Radiant floor heat

This works by heating your floors from underneath, creating an environment that is heated evenly, quietly, efficiently, and without the drying effects of forced air. Check out our story "Say Goodbye to Cold Floors with Radiant Heating" for more. This is also a good supplemental option (used in conjunction with central heat) to increase your comfort level in areas where you may have cold floors, such as a bathroom, shower, or uncarpeted area.


This uses a wall-mounted unit, called a cassette, that provides both heat and air-conditioning without ductwork.  Find out more about mini-splits from our previous blog story here, and in our post about Panasonic's Exterios mini-split which uses inverter and room occupancy technologies.  Mini-splits are available in different sizes and offer a variety of features, including remote control. They are quiet, since the "noisy" part is outside. Plus, compared to central heating systems, they are super-efficient because they eliminate ductwork, which is a source of heat loss.

Baseboard heat

These are typically electric metal heating elements that sit inconspicuously below windows along the baseboard around a room's periphery. They heat through convection, not forced air.  They are quiet, since there are no blowers.  Because they are installed near the floor and heat naturally rises, and they use no ductwork, they are efficient, too.


Portable room heaters

These are space heaters you can buy at any big box or hardware store. They can be plugged into any wall electrical outlet and can be carried from room to room as needed. There are many kinds and sizes with different types of on/off, timer, remote control, and fan features, and there are a variety of technologies used: radiant, convection, ceramic, infrared, quartz, or oil-filled (sealed).


Fireplace or wood stove with blower

These burn wood, wood pellets, or other biomass fuel (corn, nutshells, switchgrass, etc.).  By installing a blower, a huge portion of the heat that would otherwise go up in smoke through the chimney is captured and sent back into the room. The blower requires an electrical outlet for the fan and can be thermostatically controlled. It is important to note that in addition to having access to wood or wood pellets which must be stored on-site, this type of solution causes creosote buildup in the chimney and thus requires yearly chimney cleaning.  It also creates more atmospheric CO2 than some alternative solutions.

Be sure to check out the pros and cons of each heating solution before making a purchase. Whatever you choose, we wish you and yours a warm holiday season.


Posted on 12/15/2015 6:03 AM by Tony Anderson
Tuesday, 01 December 2015

It used to be that if you had central heat, you had either a gas furnace or an electric heat pump.  But with energy costs and environmental concerns playing a more prominent role in our energy choices, high-efficiency, clean or renewable energy sources have taken off.  Geothermal or ground source heating meets all these concerns!  So it comes as no surprise that from now (program was established in 2009) through December 31, 2016 (more than a year from now), homeowners who install EnergyStar-certified geothermal heat pumps are eligible for a 30% federal tax credit.


Energy Efficiency

Geothermal heat pumps (GHPs) are among the most efficient and comfortable heating and cooling technologies currently available. EnergyStar-certified geothermal heat pumps are over 45% more energy efficient than standard furnace or heat pump options. Geothermal technology uses the earth's natural heat to provide heating, cooling, and often, water heating, too! GHPs equipped with a device called a "desuperheater" can heat household water. During the summer, the heat that is taken out of the house is used to heat the water for free. In the winter, water heating costs are reduced by about half. 

Clean Energy

Most importantly, geothermal is a clean energy technology you can feel good about. It does not burn fossil fuels, so it reduces our dependence on foreign oil. In fact, closed loop geothermal systems release essentially no emissions or toxic gases. Because there is an unlimited amount of heat generated by the Earth's core, it is a sustainable energy source.

Ways to Offset Costs

The costs for installing a geothermal system are pretty steep, so it's a good thing that Uncle Sam is willing to help out!  But, a geothermal system can pay for itself in 3-8 years and add significant resale value to your home. It may also be possible to include the purchase of a geothermal system in an "energy-efficient mortgage" that would cover installation costs and other energy-saving improvements to the home. When included in a mortgage, your investment in geothermal will produce a positive cash flow from the beginning. For example, the installation cost of a geothermal system may add $30 per month to each mortgage payment, but the energy cost savings easily exceed that over the course of each year.

Many Options

Besides the 30% federal tax credit, there are a multitude of other provisions and incentives available from federal, state, and local governments, power providers, and banks or mortgage companies. These include loan programs, rebates, property tax or sales tax incentives, and grants. Check these out at the  DSIRE website, or on the EnergyStar website run by the U.S. Dept. of Energy. While you're at it, check out our other posts on geothermal:

Tis the Season

The season for saving on geothermal goes through 2016. That means there are only about 270 shopping days left (excluding weekends and holidays)!  Get your 30% federal tax credit now and start reaping the cost benefits and environmental benefits every day. 

Posted on 12/01/2015 4:01 AM by Eddie Hutton
Sunday, 15 November 2015

Holiday Feasts Eating

This time of year, your home becomes the center for family gatherings, Thanksgiving feasts, parties, etc., and your thoughts turn to holiday decorations, gift-giving and food. Here are some tips to help ensure a happy, warm, and safe holiday season.




While they set a delightful holiday ambiance, fireplaces can waste a lot of energy, as they pull warm air out of the house and force it out through the chimney.  Make sure the damper is closed and that if you do use the fireplace, do so for as short a time as possible.  Tip: Get your fireplace chimney flue cleaned yearly!​


Do not block registers or air returns with furniture, drapes, or holiday decorations. This can cause uneven heating, and could even cause your HVAC system to fail. Try using the new LED lights this year as they use much less power and give off almost no heat. Tip: Use caution when decorating with candles and non-LED lights, as they are the common causes of home fires this time of year.



 Traveling to visit relatives or to get away during the holidays?  Do not turn off your heat when leaving!  You may think you're saving money by not running the heat when no one is home, but if your pipes burst from the freezing and thawing, you could be coming home to a very costly mess!   Tip: Leave the heat on low, and have someone check your house while you're gone.

Room comfort

During cold weather, increased use of your heater causes the home and its interior air to become dry.  Using a humidifier can help add needed moisture to the air, reduce static electricity, and improve health issues like dry sinuses.  But did you know a humidifier can actually save energy?  That's because moist air holds heat, so you feel more comfortable at a lower heat setting.


furnace clutterTo allow for holiday decorations, parties, or overnight guests in your home, you might need to do some re-arranging. While you may want to store stuff out-of-sight, be careful not to store anything too close to your HVAC equipment.  Not only is it a safety hazard, but HVAC systems need air in order to burn properly and to draft, or carry the harmful by-products of combustion like carbon monoxide gases - out the flue. Tip:  Keep all clutter at least 3 feet away from your HVAC system.

Loss of heat

  A host's worse nightmare is that company is coming and you notice that the heat is not working.  Check out our post "No Heat? What Should You Do?" for things you can do to diagnose and fix many heating problems.  If all these tips fail to alleviate the problem, then call the professionals.

We wish you and yours a very happy, warm, and safe holiday season.  Let the (h)eating begin! 

Posted on 11/15/2015 8:06 AM by Tony Anderson
Sunday, 01 November 2015

Fall and spring are great times to do small maintenance jobs around the house, before the extreme cold or hot weather sets in.  It is a good idea to make cleaning the vents and ducts part of your yearly spring and fall cleaning routine. After watching the video try out this fun Test your knowledge.


Follow these easy steps:

  1. Turn your HVAC system to the off position by flipping the switch on your thermostat, or turn it down to where the system is no longer running. You do not want the system blowing air (in or out) while you are cleaning it!
  2. Remove the vent cover or open the grill's latch to expose the duct.
  3. Do a visual inspection of the duct in case there is something that can be retrieved such as an earring, a coin, a pet toy, or other small object which has fallen in. Floor registers are particularly susceptible to things falling in.  Registers on the wall or in the ceiling are probably more susceptible to cobwebs. 
  4. Using your vacuum cleaner nozzle, a handheld vacuum, or a cloth, remove spider webs or any debris that may have fallen into the duct. Be careful not to damage the ductwork while cleaning it.
  5. Clean and replace the register cover.  Then close the grill cover back over the duct.
  6. Turn your HVAC system back on by flipping the appropriate switch on your thermostat.

Do this type of maintenance twice per year, as part of your spring and fall cleaning routine. In high-traffic and very dusty environments, or if you're plagued by lots of pet hair, you may need to do this type of maintenance each time you change your air filters, which for most folks is about every 3 months.

Fall and spring are great times to get an HVAC tune-up, too, to make sure you're ready for the upcoming heating or cooling season. And don't forget to change those air filters!


Posted on 11/01/2015 3:06 AM by Tony Anderson
Thursday, 15 October 2015

AHome-for-salere you looking to buy a home or just recently purchased one? If you purchased an older home, perhaps it had significant updates new kitchen appliances or countertops, for example -  but what about the heating and air-conditioning systems?  Repairing or replacing your HVAC units can be a major expense to a new homeowner, not to mention a potential hazard! Here are some important things to consider.

Age of Systems

An HVAC system generally lasts about 10-15 years.  If the systems are older than that, perhaps you want to negotiate a deal with the seller for an update allowance. It is generally not a good idea to force the seller to install a new system as a condition of the sale, because the seller will be inclined to purchase the least expensive unit, which may not meet your needs.


If you're buying a new house (new construction), check that your new home warranty covers the heating and air-conditioning systems. If you're buying a pre-owned home with a recently-replaced HVAC unit, ask the seller for a copy of the warranty.  If the seller had the systems under a yearly maintenance contract, find out of there are future maintenance visits due.

Gas Heat

If you purchased a home with a gas furnace more than about 10 years old, we strongly recommend you have it checked by a certified technician prior to the heating season.  This is because as we said in our last post  your furnace can kill you.  Even if your furnace checks out okay, be sure you have carbon monoxide detectors installed on every level of the home, near the sleeping areas, and in the garage. 


Perhaps when you attended the open house, they had some pleasant-smelling potpourri wafting through the house. Now that you've moved in, you notice it smells like dirty sox! This can be a sign of standing water in the evaporator coil pan or holes in the ductwork, either of which requires immediate attention. Don't just cover up smells, find the cause!


Does the HVAC unit make harsh sounds when cycling on or off?  Is it really loud all the time while it's running?  If you're looking at the house on a nice spring or fall day when the air or heat is not actively running, you may be in for a surprise later!


Signs of Damage or Problems

By physically inspecting the HVAC unit, you can often see clues that something isn't right.  Is there rust anywhere on the system, ductwork, or flue?  Are there any cracked, dented, broken or exposed pipes, flues, or ducts?  Is there water leaking out of any part of the unit?  Do you see evidence that there has been a condensation leak such as constant dampness?  Is the indoor or outdoor unit covered in debris?  When the heat or air kicks in, do the house lights dim?  All of these conditions require attention by a qualified technician.


Is the airflow poor or weak in part of the house?  Does the heat blow cold air, or does the air conditioner blow warm air?  Does the thermostat work as intended?  Try to test these things before purchase or have them tested as part of a home inspection or HVAC maintenance visit.  Once you've closed on the house, it will be too late to request that these things be fixed by the seller, and it will be your problem.


Utility Bills

About half your yearly energy bills go towards heating and cooling.  Ask the seller to disclose their past utility bills.  This will give you an idea of how efficient the HVAC unit is, as well as how well the house is insulated.  If you've already moved in and find your utility bills vary drastically from what the seller had reported, this may be a sign of a problem as well.

What's Your SEER?

Visually check the unit itself for the SEER rating and Energy Star stickers.  If the SEER is less than 10, a new unit might be cost-effective.  The minimum SEER rating of systems now is 14 or greater.

We hope you found these tips helpful. Let us hear of any other questions/concerns you have, and subscribe to our blog so you won't miss out on useful tips that can save you money and help keep you and your family safe year-round.



Posted on 10/15/2015 6:44 AM by Tony Anderson
Wednesday, 30 September 2015

Every year, many deaths are attributed to home heating hazards which cause fires, carbon monoxide poisoning, and other calamities. Here are some very important steps you can take to reduce or eliminate some heating safety hazards:


Steps You Can Take

First, check the area around your furnace. Is there adequate clearance all around the system?  Or are you using the area for storage, thus limiting the system's air intake? 

Next, notice any leaks or moisture sources near the furnace, or signs of rust in the furnace.  Something as simple as condensation dripping from a cold water pipe onto the furnace can cause rust.  Rust on the inside or outside, or along any of the vents is a carbon monoxide hazard.  Other potential carbon monoxide hazards include animal or bird nests obstructing the flue, soot build-up, improper venting, and damage or deterioration to any vents.

Carbon Monoxide Dangers

According to the Centers for Disease Control and Prevention, there are an average of 430 deaths per year in the United States from unintentional, non-fire-related carbon monoxide  poisoning.  The older the furnace, the more likely there could be a problem. Carbon monoxide is a sneaky problem for many reasons.

  • First, carbon monoxide is colorless and odorless… it's not like natural gas which has the smell of rotten eggs!  Thus, it is difficult to know that you've developed a carbon monoxide leak. That's why it's nicknamed "the silent killer."
  • Second, your heat may be operating (keeping the house warm) so you do not know that your heat exchanger or vent is beginning to rust out and building up the deadly gas..
  • Lastly, low-level carbon monoxide poisoning mimics the symptoms of common winter ailments - such as the flu, or an over-indulgent night out, or even seasonal depression - so many cases are not detected until permanent damage to the body has occurred.  
Symptoms of carbon monoxide poisoning include: headache, nausea, vomiting, dizziness, fatigue, shortness of breath, and eventually, loss of consciousness.  

Tips for Prevention

The U.S. Consumer Product Safety Commission, recommends these tips:

  1. Have all fuel-burning home heating systems inspected and serviced annually by trained service technicians.
  2. Install CO detectors with battery backup in hallways near each sleeping area and in the garage.  Test the CO alarms and replace the batteries every year.

Test your knowledge.

Following these important tips can keep illness or death from claiming your life or the lives of your loved ones.

Posted on 09/30/2015 11:53 PM by Tony Anderson
Tuesday, 15 September 2015

Well, the short answer is, "it depends."  Ask yourself these questions:

What is included?

If the contract is very cheap, it may be just a ploy to get a technician into your house and try to sell you something you don't need.  However, if the contract entitles you to a discount on parts or labor, or priority service or emergency/after-hours support, then it might be very well worth it!  If a system is going to break down, it will typically do so at extreme temperatures: the air conditioning will fail on a very hot, humid day, or the heat will fail during a prolonged stretch of frigid weather.  These are times when you can ill afford to be without a working system and when all HVAC companies are inundated with calls.  Without having a company that will put you to the front of the line, you might find the wait with any company you call will be measured in days, not hours!  Additionally, most HVAC companies will charge extra for after-hours support.  You could wind up paying up to twice the labor charges for getting your system serviced on a Saturday versus getting it serviced on Monday.  But in extreme temperatures, you may not be able to wait until Monday!  So, if your service contract entitles you to no additional up-charges for after-hours emergencies, the savings in the labor on just one visit could be worth it.

How old is your unit?

If you have a brand new unit (less than 6 years old), the chances of it breaking down might be less than if you have a unit that is more than 10 years old.  Also, if the unit is still under warranty, then it could be that some portion of parts and/or labor may be covered by the warranty.  But be aware that manufacturers may not honor the warranty if they think the unit has not been properly maintained by the homeowner. Having a service contract where you can prove the unit had regular preventive maintenance might make all the difference.  Certainly, if you have an older unit, or a unit with a history of previous failures, having a service contract might be a smart move!

How diligent are you in doing preventive maintenance?

If you're following the tips we provide on our HVAC News page, videos, and in our Fall Maintenance eBook, and are diligent about changing filters on time, cleaning the coils, keeping the condensate line clear, and doing other recommended tasks yourself, then you might not gain that much from having a service contract, especially if it only includes these same types of services.  Of course, some preventive maintenance tasks require special equipment, measuring devices, certifications or licensures (such as adding refrigerant to a unit), so there's no such thing as never needing service.  But if you're pretty handy and diligent about doing all you can, you certainly will lessen the chances of some things going wrong.

Consider Potential Savings

Annual maintenance is vital to keep your HVAC system in good working condition and at peak efficiency, so you'll benefit by (a) avoiding big repairs bills, since minor problems could be spotted before they escalate, (b) lowering your utility bills, since your unit will be running more efficiently, and (c) extending the life of your system, so purchasing a new system can be delayed. Like your car, it is cheaper to maintain it in good working order than to deal with large repair bills when it breaks down.   

Read  the Fine Print

Always read the contract, so you understand exactly what's included, and what's not.  For example, if you purchased a service contract from the gas company thinking it will cover your furnace maintenance, you may find it only covers repairs to the gas lines from the street up to the furnace; the gas company won't be coming out twice a year for tune-ups and regular preventive maintenance on your HVAC unit.


Consider the Company, Not Just the Price

Remember, the service contract is only as good as the service provider backing it up. Are they honest, trustworthy, and reputable? Are their technicians trained, certified, licensed and insured?  Do they have experience with the type of equipment you have?  Do they treat their customers with respect?  Do they have good online reviews by homeowners (or business owners) and by the Better Business Bureau (BBB)?  Have they been in business a long time?  If you base your service decisions solely on price, you may not be getting a good value for your money.

Posted on 09/15/2015 7:39 AM by Tony Anderson
Monday, 31 August 2015


Heat pumps provide both heating and cooling, so they are very practical for Tennessee's climate. High-efficiency heat pumps also dehumidify better than standard central air conditioners, resulting in less energy usage and more cooling comfort in summer months. However, the efficiency of most heat pumps as a heat source drops dramatically at low temperatures, generally making them unsuitable for cold climates.

Technology Advances

The new crop of heat pumps offer technology advances that not only make heat pumps perform much better during extreme temperatures, but also double the efficiencies of 10 years ago. Indeed, the market has been heating up for heat pumps growing by double-digits in each of the last 2 years! Here are a few of the advanced features:  

  • Inverter Technology: varies the flow of refrigerant and adjusts the speed of the compressor according to the desired temperature and the current room temperature. By eliminating the cycling on and off of the compressor, efficiency is increased, and the temperature stays more steady.
  • Two-Speed Compressors: save energy, reduce compressor wear, and allow zone control (keeping different rooms at different temperatures).
  • Variable-Speed Blowers: allow the fans to keep the air moving, minimizing cold drafts, reducing noise from the blower, while also maximizing electrical savings.
  • Scroll Compressor: consists of two spiral-shaped scrolls - one remains stationary, while the other compresses the refrigerant. Compared to the typical piston compressors, scroll compressors have a longer operating life, are quieter, and provide 10-15°F warmer air when in the heating mode.
  • Back-up Burners: rather than using electric resistance heaters as a backup heat source during extreme cold weather, some manufacturers now use a combustion fuel source such as propane, natural gas, oil, coal, or wood, thus reducing the use of electricity.
  • Refrigerants: the new crop of heat pumps use the more environmentally-friendly and less costly refrigerants, and new refrigerant formulations transfer, hold and deliver heat more effectively. Plus, the copper tubing through which the refrigerant travels has grooves on it to increase surface area, which also boosts efficiency.
  • Computer-controlled motors and valves: consume less electricity and provide more precise control of the refrigerant flow.
  • Electronic, programmable  thermostats: many of which are now wireless or Internet-capable, allow additional savings and conveniences. Check out our previous blogs on thermostats.

What to Look For

Energy Star Label showing SEER and HSPF

When shopping for a new heat pump system, check the Energy STAR® label and compare the HSPF rating (heating season performance factor) which is an indicator of the efficiency of the compressor and the electric-resistance elements and the SEER rating (seasonal energy efficiency rating), which rates a heat pump's cooling capacity (see our post What's Your SEER?).  HSPF should be between 8 and 10 and SEER should be greater than 14. In both cases, the higher the number, the more efficient the unit.


Posted on 08/31/2015 2:14 AM by Tony Anderson
Saturday, 15 August 2015

In a previous posting, we discussed the basics of vents, registers, and air grilles. This article deals with some of the various gadgets you may use along with your vents.  Keep those questions coming in we love to hear from you!  

What about magnetic vent covers or just closing the vents?

Magnetic vent covers are pieces of flexible material that sit on top of and cover the vent grille, effectively blocking off the flow of air. Most vent grilles also have a small knob which controls louvers, to allow you to alter the direction the air blows or to close the louvers completely to prevent air flow.  We recommend only using magnetic vent covers or closing the louvers in special circumstances and for as short a time as possible.  For example, if you have one room of your house you never use in the winter, then you can close the vents in that room to avoid heating it, and to force the heat into the other areas of the house. But you must make sure that the door to the room you are closing off stays closed and that the return air grille is not located in or near that room.  A better solution would be to create a separate zone for that room.

When should air deflectors be used?

Air defectors are typically clear plastic attachments to the vent or register grille that direct the flow of air in one direction. This is sometimes a good idea when the vent falls in an awkward place in the room in relation to drapes or furniture. It is far better to use a deflector than to use a vent cover or close the vent entirely. Always deflect the air into the room (towards the room occupants) and not towards an exterior wall or window. Remember that the deflector will also need periodic cleaning.


Are vent filters a good idea?

These are similar to air filters, and are typically made of a mesh material that allows air to pass but traps larger particles. HEPA vent filters may be helpful to people who are particularly sensitive to pollen, mold, pet dander, and other allergens. Some filters are impregnated with charcoal to help take odors out of the air. Other than some particular circumstances, vent filters are not generally recommended.  They impede the flow of air and make your system work harder than it needs to. If your objective is to keep the air clean of particulate matter such as pollens and dust, it is much more effective to put a good quality air filter on the return air grille than to insert filters into each individual register.  Keep in mind also, that filters only work when the HVAC blower is running (air is actively blowing).  The rest of the time, pollen, mold spores, and other allergens are all around, coming through doors and windows, and riding along on our clothes and furniture. For people who are ultra-sensitive, an air purifier might be a better solution than vent filters.

Vent/Register fans

Check out a previous post we wrote on register fans: Are Register & Duct Fans a Solution for Uneven Heating & Cooling?

Tell us about any gadgets you've come across, and what you like or dislike about them.  As always, we welcome your comments and feedback. 

Posted on 08/15/2015 4:55 AM by Tony Anderson
Saturday, 01 August 2015


In Tennessee, the humidity can be unbearable at times, making air-conditioning a necessity.  Air-conditioning removes the excess humidity and thus makes us feel more comfortable. But signs your home suffers from excess humidity include: mold, mildew, dust mites, bacteria, rotting or warping wood inside your home (cabinets, wall beams, floors, furniture), or peeling paint; plus, the moisture attracts pests (even snakes!).  What can be done? Perhaps you've contemplated getting a dehumidifier, but even the best dehumidifier may not work effectively if too much outside moisture is seeping into your home.

Humidity Checklist

Before making an expensive dehumidifier purchase, be sure you have investigated these issues:

  • Check that gutters aren't clogged and that downspouts are directing rainwater at least 3 feet away from the house. Grade your property so that rainwater flows away from the foundation.
  • Keep the duct for your clothes dryer properly vented to the outside, making sure that it isn't clogged or leaking.
  • Run an exhaust fan when showering, and squeegee or wipe down shower walls afterward.
  • When cooking, use a range hood or exhaust fan that vents outdoors.
  • Use ceiling fans and room fans to keep the air circulated. This will help your air-conditioner be more efficient.
  • Look for leaks in your existing ductwork that need to be repaired. Leaks let cool air escape into the attic or crawl space. That air loss creates negative pressure inside, causing it to suck in humid air through cracks. See about getting your ducts tested and sealed.
  • Check your plumbing for leaks and condensation, especially in the basement, and insulate pipes.
  • If you have extensive water or drainage problems, it may require a sump pump and installing drains outside.

Basements & Crawlspaces are the Most Problematic

Most HVAC systems naturally pull air from the lower areas of your home upwards throughout the living space; thus a damp basement or crawlspace can affect your whole house. Crawlspaces, while they may have fewer cubic feet due to the lower ceiling height are actually harder to dehumidify because they require more airflow (air pressure) to circulate air.  This is why a good crawlspace dehumidifier costs more than an average home dehumidifier. Waterproof your crawlspace and basement, and ensure it is properly insulated.  Fill holes and cracks in concrete block with hydraulic cement and paint the concrete block with a water-proof coating like Dry-Lok. If your crawlspace has a dirt floor, create a vapor barrier to reduce the continual evaporation of moisture from the ground.

Is your HVAC to Blame?

Lastly, your HVAC system itself may be to blame for your excessive moisture problem! If you over-sized your system thinking it would make you cooler and not run as hard in the summer, think again! Air conditioners only dehumidify when they are running, and an oversized unit may not be running long enough to remove the moisture from the air (it cycles off too quickly). Check out a previous post we did on right-sizing your system entitled "Think Bigger is Better? Not When it Comes to Cooling!"

After you've addressed these causes of excess humidity, then you can see if a dehumidifier is needed. We did a post recently about central dehumidifiers, so check that out, too!

Posted on 08/01/2015 3:44 AM by Tony Anderson
Wednesday, 15 July 2015

In Tennessee, the humidity can be stifling, especially in the summer! The average morning relative humidity in Nashville during the months of May through October is 85-90%yet the optimal comfort zone, as published by ASHRAE, is 30-60%. We're taught to seal up cracks and tighten up our homes so as not to waste energy, but tighter homes can also trap moisture, creating an unhealthy environment. Excessive humidity encourages the growth of mold, mildew, dust mites and bacteria, which in turn worsens allergies and respiratory ailments. In addition, excess moisture can lead to wood rot or warping of floors, beams, cabinets and molding, and cause paint to peel and wallpaper to curl.  If your windows are wet with condensation or you're having to run your air conditioner so much that you need to sleep with a blanket in the summer, then dehumidification may be necessary.

Portable vs. Central Dehumidifiers

Portable dehumidifiers treat the air in just one room and have a reservoir that needs to be emptied daily in most cases. Central dehumidifiers are connected to your home's heating and cooling system and treat the whole house. A central dehumidifier pulls air from every room in your home through the return ducts, removes the moisture, and then sends dry air back throughout your home. Unlike a portable dehumidifier, a central dehumidifier is located out-of-sight, is quiet, and hassle-free because you never have to empty a reservoir it is attached directly to your house plumbing.  A central dehumidifier is up to 4-times more energy-efficient than the leading portable dehumidifier (look for ones that are Energy Star rated). Portable systems can remove 5-7 gallons of moisture per day, while a central system can remove 40+ gallons per day.

Features, Functions, and Savings

A central dehumidifier measures the condition of your home's air to decide when to run and is automatically controlled. The desired humidity level can be set to a fixed percentage for a constant comfortable humidity, regardless of how the outside air increases or decreases in humidity. Although the method of control varies depending on the model and manufacturer, many whole-house dehumidifiers have user-friendly digital controls or remote controls. By using a dedicated central dehumidifier along with air conditioning, you can save energy because you'll be able to increase your thermostat in the summer by at least 3 degrees and be more comfortable.  Many dehumidifiers also provide ventilation and/or air purification, thus greatly increasing the quality of your indoor air and helping allergy sufferers.

The Downside

  • Central dehumidifiers can be expensive, ranging from $400 for a 1200 sq.ft. space, to $16,000 for a 2500 sq.ft. home.
  • Installation requires specific tools, electrical wiring and plumbing. It generally is not a do-it-yourself task. A trained HVAC technician would need to install it.
  • Because central dehumidifiers are built into the ductwork of your home, when you move, they will need to be left behind.

Moisture can lead to costly renovations or mold remediation, so a central dehumidifier may be a wise choice.  But even the best dehumidifier may not work effectively if too much outside moisture seeps into your home from leaky ductwork, a damp crawlspace or basement, improper drainage around your home, or an improperly-sized HVAC unit. You'll want to investigate and fix these issues before spending money on a whole-house dehumidifier.


Posted on 07/15/2015 7:27 AM by Tony Anderson
Wednesday, 01 July 2015

It's summer and it's hot, and with the humidity it's way uncomfortable!  Your air conditioning may not seem to be cooling as well as it used to, or it seems it's having to work overtime to get it cool.  Well, you figure, it's nothing that a shot of Freon can't fix… how expensive can that be? Unfortunately, a lot!

You see, the federal regulations phasing out the "old" Freon known as R-22 means that there is a very limited supply of it.  Like anything driven by supply and demand, as the supply of R-22 has become more restricted and the demand has gone up, the costs have soared.  A shot of Freon a couple of years ago that cost you only about $50 could cost close to $400 now! Some folks have even nick-named R-22 "Liquid Gold." Plus, once 2020 rolls around, R-22 production will be phased out entirely, and will be illegal to import or export.

But there's a bigger issue here. The refrigerant R-22 exists in a closed loop constantly being recirculated inside your system. It is not consumed by the system, so, it should never need replacement.  If your system is running low on refrigerant, that means you have a leak!  Rather than continuing to pay the increased costs to replenish the leaking R-22, the better solution is to find a qualified heating and cooling company to find and repair the leak, wherever it may be.

After the HVAC technician has inspected your system thoroughly, you'll know whether it makes sense to continue investing in your existing system (fixing the source of the leak and replacing the R-22) or whether it makes better sense to purchase a new system.  New systems no longer use R-22 as a refrigerant they use the more environmentally-friendly R-410A, which is a LOT cheaper!  Plus, new systems have been mandated by the government to be more energy efficient, so you'll save money in the long run.

Unfortunately, you can't just put the new refrigerant (R-410A) into an old system designed for R-22.  They operate at different pressures, and your existing evaporator and condenser were not designed to operate at these increased pressures. Plus, R-410A systems require a different type of oil and expansion valve. So, it comes back to the age-old "repair or replace" question.

System leaks can not only harm the environment, but also result in increased operation and maintenance costs.  So, don't sink a few hundred dollars into Freon that will just leak back out!  Get that leak fixed now! 

Posted on 07/01/2015 7:20 AM by Eddie Hutton
Monday, 15 June 2015







As we enter the summer months, high air-conditioning bills seem just as inevitable as death and taxes.  Something most people don't think about is that incandescent and halogen bulbs act as miniature space heaters, dumping over 90% of the energy they consume into heat… heating up your already-hot home. This means your air-conditioning has to work harder to keep you cool.  LED lighting uses a fraction of the energy consumed by traditional light sources.  They generate very little heat  (3 BTUs/hr vs. 85 BTUs/hr for incandescent bulbs) and remain cool during operation, thus easing the burden on your air conditioning system during hot weather and reducing your overall energy costs.  For every 60W incandescent (traditional) light bulb, you're spending about $13.86 more in cooling costs per year (based on Nashville/TVA's current electricity rate of 10.252 cents per kilowatt-hour) versus an equivalent LED bulb, so it can quickly add up!  Even when you consider the initial cost of LED bulbs (currently about $2.48 for a 60W equivalent bulb, compared to about $1.00 for a traditional 60W bulb), the payback period is just 6 months for a light that stays on 8 hours per day..  The savings come from reduced electricity to produce the light as well as the reduced cooling costs.  And just in case you're thinking that the heat generated from traditional lighting might be beneficial in the winter to help keep you warm, it's an extremely inefficient heat source, costing over 5 times as much as the typical gas furnace to generate the equivalent amount of heat.  Compact fluorescent light bulbs (CFLs) were promoted as an energy-saving alternative, but they're no match for LED lighting, and are falling out of favor.

LED stands for light-emitting diode. The light is generated by a semiconductor, creating an effect known as electroluminescence.

Residential Advantages

  • LEDs do not contain mercury or toxic materials. However, CFLs contain mercury, which makes them hazardous to handle and to dispose of.
  • LEDs are much more durable than incandescent bulbs because they will not shatter when jarred or hit, and are not sensitive to humidity.  Both CFLs and incandescent lights are fragile.
  • LEDs have a longer life than any other lighting source on the market.  This means reduced hassle and inconvenience of replacing burned-out light bulbs. You would need 42 incandescent bulbs (changing the bulb 41 times!) to equal the typical 50,000 hr lifespan of an LED bulb.
  • Because LEDs run so much cooler than other bulbs, they are safer.  Lighting a holiday tree or other lighting decorations using incandescent lights presents a fire hazard due to the extreme concentrated heat they produce.  Plus LEDs won't overload wall sockets by stringing multiple strands together.
  • LEDs are available in a range of hues, from remarkably bright white, to warm golden, to cool blue. 
  • LEDs offer design flexibility, and are available in unique styles and shapes. 
  • LEDs are an easy retrofit.  LEDs can be run with a dimmer (not true of most CFLs), which allows you to adjust the light level to suit your needs and create mood lighting.

Industrial Lighting Advantages

  • For industrial lighting applications such as warehouses, high ceiling environments, parking garages, traffic lights, etc. ─ the conversion to LED lighting would save many thousands of dollars in operating costs due to reduced electricity consumption, reduced need for bulb changes, ability to withstand shock, vibrations, and impact, and reduced demand on cooling. Plus, they are "instant on" (don't have to warm up before emitting a bright light, quiet (no "hum" typical of high-powered fluorescent lights), and don't require ballasts.
  • LEDs are a "green" solution, due to their vastly reduced energy consumption, reduced waste, and reduced toxic hazards ─ a win-win for health, safety, and the environment.

It's time to convert to LEDs now!

  • Why make your air conditioning work harder than it needs to? LEDs provide significant long-term cost savings and help you keep cool.  
  • If you are looking for ways to reduce your utility bills, increase the energy efficiency of your home and business with aesthetically pleasing lighting solutions, LEDs are currently an outstanding solution.

Posted on 06/15/2015 11:00 AM by Eddie Hutton
Monday, 01 June 2015

Repairing or replacing your heating and cooling system is one of the most critical decisions home owners face. Learn more in this short video or read the paragraph below

While there are no hard-fast rules to answer the repair or replace question, we've put together some general guidelines in an earlier post.  But perhaps the more important question is 'Do You Trust Your HVAC Specialist?' That's the REAL issue because most of us don't have the technical expertise to know whether their recommendations are sound.  Many HVAC companies pay their technicians on commission rather than an hourly rate, which means it's in their best interest to get you to replace your unit when a repair might be all you need.  Repairing often requires higher-skilled technicians, and they may need to spend more time troubleshooting the problem or retro-fitting a part. You want a company that can advise you reliably whether to repair or replace a unit based on what is in your best interest, not based on what is convenient or what earns them the most money.

If you're on the fence about whether to repair or replace your system, the best solution is to have a highly trained and qualified technician who will give you an honest assessment, and will spend the time to find the best solution to fit your needs. If you don't feel this way about your current HVAC technician, then you for sure need a replacement… a replacement of your HVAC service company, that is!

Read our HVAC News page, call us, and let us help you with what may be one of the most critical decisions for your home.

Posted on 06/01/2015 5:49 PM by Tony Anderson
Sunday, 17 May 2015

Whether you call them vent covers, floor registers, or air grilles, this article deals with the part of your HVAC's ducts that you see in the various rooms of your house.  These may be located along the floor, baseboard, or wall, and vary in size depending on the size of the ductwork.  The purpose of a vent grille is to protect the ductwork from damage and tears from things falling into it such as a person's foot or from scratching by pets or sharp objects - while at the same time allowing air to pass. 



A Decorating Statement

It's become a high-end decorating statement to have vent grilles specially coordinated with your décor.  Whether you shop at Home Depot or a boutique home accessories store, you'll see vent covers in a variety of materials, colors, finishes and designs.  Materials can be brass, bronze, cast iron, metal, steel, or wood, and they can cost anywhere from $3.00 each to $100-200 each!  Regardless, they all serve the same function and there's more to them than just the aesthetic qualities. 

Air Flow Issues

First and foremost, ensure the vents are open and unblocked by drapes or furniture. Vacuuming or stepping on a floor register could inadvertently close the register, making your HVAC system not work properly, so if you're having uneven heating or cooling, the vents/registers are the first thing to check.

When should vent covers be replaced?

Vent covers only need replacing if they become damaged (bent), corroded (rusted), or will not stay open.  Otherwise, a periodic cleaning is all they need, using a cleaner appropriate for the type of material and finish.

How often should the vent covers be cleaned?

They should be cleaned whenever they need to be, but a minimum of twice per year fall and spring is ideal.  In high traffic or dusty environments, you may want to clean them each time you replace your air filters (minimum of every 3 months).

Posted on 05/17/2015 7:45 PM by Tony Anderson
Thursday, 30 April 2015

If you are embarking on a home improvement project, such as painting a room, doing drywall repairs, or sanding/refinishing wood floors, steps must be taken to protect the ductwork from paint, sand/dust, flumes, tools, and damage.   Remove the vent registers prior to beginning work.  Then, cover the duct completely with a barrier material that can be taped all around (see photo).  A large plastic garbage bag also works very nicely. If there is danger of someone walking or positioning a ladder or tools near a duct that is covered in this fashion and thus falling in and damaging the duct put the vent grille back on top of the register.  If you have the high-end designer vents (brass, etc.), consider getting a couple of the cheap vent grilles to use temporarily during your home improvement project, so your "good" vent grilles won't inadvertently be damaged.  The last thing you want is someone putting a foot through the duct or tools falling in and tearing a hole in the duct!

Why it's so important

Tears in the ductwork or any holes require immediate attention. They will cause your HVAC system not to function properly, and your system will not cool or heat very well.  The conditioned air (the air you paid to heat and cool) will be leaking out and mixing with unconditioned air, which is then blown back through your house.  Not only is there a lot of lost energy - costing you extra money but your HVAC system will be over-worked and wear out quicker.  You may also develop a pest problem from crawling insects, rodents, or reptiles which can come through the holes in the ducts into your home. Over time, you may also develop an odor and moisture problem.  If you are experiencing any of these issues, a hole in your ductwork may be your culprit!

If you are building a new home or an addition, make sure the contractor seals all the ductwork before the drywall is installed. It is almost impossible to clean drywall dust out of ducts, so the best solution is to keep them protected from sources like this from the outset.  For more information on duct cleaning, see our earlier post.

Posted on 04/30/2015 9:00 PM by Tony Anderson
Wednesday, 15 April 2015

Tim Thomas, VP Sales & Marketing, Culer, explains how a new space cooler works and saves energy.


One of the oldest ways of conditioning air is evaporative cooling, which cools air through the evaporation of water, rather than through the use of compressors and refrigerants.   Evaporative cooling is how cars of the early 1950's were air-conditioned (see a previous post here).  A Nashville-based company called Culer has developed a new space cooler using a patented nozzle that combines water and air under low pressure to form extremely small particles of water.  When exposed to air, these water particles instantly evaporate and cool the surrounding air.  We interviewed Tim Thomas, VP of Sales & Marketing at Culer, to learn more.  Here's how he explains how their space cooler works. 

It takes a lot of energy to go from a liquid to a gas.  If you can cause evaporation, you are going to be very efficient at creating a cooling effect.   Air conditioners have to have a compressor to evaporate and then condense a refrigerant, so you are exchanging heat in a not very efficient manner.  Because it's a closed system it takes a lot of energy.  We use a low pressure pump to run a small fan inside.  Then, by using very fine water particles in a concentrated air stream, we are able make evaporation happen immediately.  The magic happens in the nozzles.  Our nozzles are what I call hydro-pneumatic:  they introduce both water and air in the same nozzle.  Based on the geometry we call flow blurring, atomization occurs inside the nozzle, and when water exits, it's already atomized.  It doesn't just rely on the pressure behind it.

How can a Culer be used in a home to save energy?  The Culer AC home series as a complementary product to an existing whole house HVAC system.  Instead of setting your air conditioner at 78 degrees you could raise it to 80-82 degrees.  Then place the AC series product in the room you are occupying, to cool that specific area or zone that you are in, thereby saving money because you're able to run your whole house system at a higher temperature.

There are several models of Culer products, each made for indoor or outdoor areas of different sizes. Our patented nozzles make our technology unique, and it is completely scalable. We can make products for the home all the way up to our professional unit, which includes six larger nozzles as well as a 30-inch fan that can handle up to 3,000 square feet and can be used in both indoor and outdoor locations. The features of the product are very simple. There is an on-off button and a control for a 3-speed fan.  The cooling effect activates the low pressure pump; this pressurizes the water which then goes up to the nozzle.  The dial in the middle allows you to fine tune the amount of water you introduce into the air stream.  For a very hot, dry environment you would set the dial to use more water, and for more humid areas you use less.  The port can be positioned up or down by 15 degrees, and rotated horizontally up to 180 degrees. To activate the unit, all you need to do is put one gallon of water in it.  For a single-port device, one gallon of water will last around 12 hours.  Pour one gallon of water into the fill port.  Put the cap back on and make sure it is sealed tightly as that tank will get pressurized.  It uses 12-volt DC power, which is compatible with any vehicle - whether it's a boat, an RV, or a standard automobile or truck -  and you can simply plug it into that vehicle's system.  The AC 200 has 2 ports and two atomizing nozzles that can be operated in independent directions, and costs only about 12-cents per day to operate.

Posted on 04/15/2015 11:25 PM by Tony Anderson
Tuesday, 31 March 2015

After a long, cold winter, spring's bright sun and warm temperatures are more than welcomed in Middle Tennessee.  But the hot summer weather is just a few weeks away and you can bet by then air conditioning repair technicians will be plenty busy!  It seems if your air conditioner is going to go out, it will do so when you need it most on one of the hottest days of the year!  Want to save money and all the hassle of an outage?  Have a pre-season check-up!  That means getting your spring maintenance visit scheduled in March or April, and getting your Fall Maintenance visit in Sept. or Oct.  To remember to schedule your pre-season check-ups, plan them around the time changes in the spring and fall.

Of course, there is really no substitute for a professional HVAC inspection, as some things a homeowner just cannot do for themselves when it involves air conditioning.  For example, refrigerants can be sold and installed only by certified technicians. Testing voltages and pressures within the equipment requires special gauges, etc.  But there are a number of very important things a homeowner CAN do for themselves.

5 Springtime Tips

1.  Check and replace your air filters.

There are several types from which to choose, depending on your needs.  We recommend buying the highest MERV rated filters to cut down on spring allergy symptoms. Turn off the power to the unit before pulling out the filter so the blower doesn't come on and blow dust throughout the system. Vacuum up any dust in the air duct.  Orient the filter according to the instructions printed on it.  Replace the filter at least every 90 days, but check it monthly and if it looks dark or clogged, change it.  If you have pets, you may need to change your filters more frequently. Not replacing filters is one of the main reasons HVAC equipment begins to fail.

2.  Check and inspect the condensate drain.

The condensate drain line carries water condensation away from the evaporator coil, and if this becomes clogged or improperly connected to the rest of the drain system, your AC system can become flooded and you could have a very bad mess on your hands!  A plugged drain can cause water damage in the house (see real story below) and will cause your system to stop working. Check the condensate tube to make sure it isn't clogged by sludge and algae, especially at the drain port. If it's a flexible tube, it should be easy to pull off and clean.  Clean it with a 50% bleach solution.  Then, periodically throughout the season, pour a cup of bleach solution down the air-conditioner condensate drain to prevent buildup of mold and algae, which can cause a clog.  Watch our video on condensate drain maintenance here.

Real story:  We had one customer who had an air conditioning unit in the attic.  One day she walked into the bedroom to find it "raining" from the ceiling!  The condensate drain got plugged up and water overflowed, causing ceiling damage and requiring replacement of all the wet insulation in the attic.

If that customer had installed a float value and checked it periodically, they could have prevented the damage. If the condensate tube becomes plugged the pan will fill with water.  Lift up the float valve and it should shut off the unit and prevent an overflow.  

3.  Clear vegetation around your AC compressor outside.

To work efficiently, the compressor needs good airflow. Prune any plant growth that could block it. Check to make sure there is at least two feet (24 36") of clearance all around it.  Weekly during spring, summer, and fall remove debris such as leaves, pollen, and twigs from the top and sides of the outdoor unit. Don't allow the lawn mower to discharge grass clippings onto the unit. If the outdoor unit is crowded by a fence or shrubs, or if the bottom few inches of the coil is buried under mulch, air-flow will be restricted, which decreases efficiency, reduces the life span, and damages the unit.

Tip:  When doing your spring planting, allow room for long-term growth, 5 to 10 years down the line. If building a fence, make sure it can be easily opened or removed. The unit needs to be serviced regularly, and the technician may need access to all sides of the unit.

4.  Check the outdoor unit's foundation.

Ensure that the outdoor air-conditioning unit is on firm and level ground.  This is typically a concrete pad, but could also be plastic or rubber. Settling, erosion, flooding, or ice damage may occur throughout the year, causing the pad to crack, sink, or become unleveled.  This puts strain on coolant lines, and could bend or break copper or electrical lines, or cause water to puddle in the unit.  Before trying to level the unit yourself, contact a technician to properly disconnect the unit. Make sure the pad raises the unit out of the dirt and that there is adequate drainage around it, so that water does not pool near it during a hard rain.

5. Clean the condenser fins, coils and fan (the outside unit).

Dirty coils reduce the system's ability to cool your home and cause the system to run longer, increasing energy costs and reducing the life of the equipment. The fan inside the condenser coil sucks air through the fins, and as a result, pulls dirt and debris with it. Fins are the fine metallic blades that surround the unit.  Clean the outdoor unit when the temperature is 60 degrees F or higher. Before cleaning it, be sure the power is turned off.  There may be a 240-volt power box near the unit which can be unplugged or turned off, or you may need to turn the power off at the circuit breaker. Using a garden hose, spray water on and through the unit, washing the dirt and grime off the fan and coils, cleaning the fins, and removing any debris like leaves or cut grass that may have become lodged in the unit.  If desired, you could also use a foaming coil cleaner (sold at most hardware stores), following the directions on the can.

Compressors can be fragile and so require special start-up procedures. First, make sure your inside thermostat is set to "off" (not in the "cool" setting).  Restore the power to the outdoor unit, either by plugging it in again or flipping the circuit breaker back on.  Wait 10-30 minutes before turning the thermostat into the "Cool" position. Listen for odd noises.

Tip:  If you switch off the air conditioner (at the thermostat) at any time, wait at least five minutes before switching it back on. Once off, the compressor needs time to "decompress." If you restart it too soon, you'll stress the motor. Many thermostats have automatic time delays built into the circuitry to protect the compressor from this problem.

The Payoff

Few routine chores will pay off more handsomely, both in comfort and in dollars saved, than a simple air-conditioner cleaning. The payoff: Summertime comfort and lower cooling bills. You'll also prolong the life of your air conditioner.  Having a pre-season check-up is the best way to ensure your HVAC equipment is operating at peak performance, and the best way to prevent future problems and unwanted costs.

Posted on 03/31/2015 10:00 PM by Tony Anderson
Sunday, 01 March 2015

One of the reasons we write this HVAC News column is to empower you with information.  Many times that means telling you how to do things yourself to save money on your HVAC maintenance or energy bills.  But this time, we're emphasizing a few things you should never do because they can be harmful or cause injury to you or your HVAC system.  As we always say, knowledge is power!

  1.  Do not cover your outdoor HVAC unit.  Many people falsely believe they should cover their outdoor unit to protect it from the elements, like rain and snow.  The only time it may be covered is if it's turned completely off.  While the unit is on and operational, it must have good air flow all around it in order for it to operate, and you will damage the unit if you operate it with a cover on.  It's ok for the unit to be located underneath an overhang, as long as there are no obstructions for about 3 feet all the way around it.
  2. Do not use a de-humidifier in the winter or a humidifier in the summer.  In the winter, the heat removes the air's natural humidity, and the dry air increases static electricity, makes respiratory passages uncomfortable (aggravating allergy and asthma symptoms), causes itchy skin, damages the woodwork and wood flooring in your home (causing cracking/splitting), and increases your energy bills.  That's why you want to use a humidifier (not de-humidifier) during the winter. Here in TN, we naturally have high humidity in the summer so it would be counter-productive to use a humidifier in the summer, plus it would increase mold and insects.  Air-conditioning helps you feel more comfortable in part by taking the excess humidity out of the air, and using a de-humidifier (not a humidifier) can help even more!  
  3. Do not use your fireplace as your main heat source.  Some people think that in cold weather, it will help keep their house warmer if they use their fireplace in addition to their HVAC system.  This is dead wrong.  The fireplace causes already warmed room air to be sucked up the chimney and thus makes the house colder… and causes you to use more energy (increasing your utility bills).  The fireplace may be a nice touch for "ambiance" for a few minutes, but should not be used as the main heat source unless it is an emergency and all your heat and power is out.  Additionally, using the fireplace greatly increases indoor air pollution (particulate, soot, and toxic chemicals in the air), and can trigger allergies.
  4. Do not over-size your HVAC system.  When purchasing a new system, it is easy to think bigger is better, but not so when it comes to HVAC systems!  A properly-sized piece of equipment that's not too large is going to work much more efficiently in maintaining better and more even comfort in your home.  Check out our previous post about this issue here.
  5. Do not ignore small issues like smells, sounds, leaks or minor heating/cooling problems.  These have a way of becoming big problems before too long, and the longer the issue persists, the more money it may wind up costing you.  Money Magazine recommends the best thing you can do to save money is have regular maintenance of your HVAC system twice per year.  Don't bury your head in the sand and hope for the best.
  6. Do not block registers, air returns, or forget to change your air filters.  These are the number one reasons HVAC systems fail or have problems like uneven heating and cooling.  Set up a reminder on your computer or smartphone to change air filters a minimum of every 3 months. If you're blocking registers in an effort to deflect air to the rooms that need it most, then read our post on uneven heating and cooling solutions here.  It's better to get to the root cause of the problem than to deal with a symptom of the problem in this manner, as it will only harm your HVAC system and shorten its life if you block registers or air returns.
  7. Do not turn off your heat when leaving for vacation during the winter.  You may think you're saving money by not running the heat when no one is home, but if your pipes burst from the freezing and thawing, you could be coming home to a very costly mess!  In fact, it's a good idea to turn off the water to the house (via the main cutoff valve), and then open up all the faucets so there is no possibility of frozen pipes.  That's because if the power goes out while you're gone, the heat won't work and, if the outage is prolonged, any liquid in the house could freeze anyway. Turn the icemaker off in your freezer and drain the water line, and drain the water from the toilet tanks.


Posted on 03/01/2015 6:50 AM by Tony Anderson
Wednesday, 18 February 2015

It is not often that Nashville experiences extreme cold weather for several days in a row, so this year has been quite unusual in that regard.  Everyone is worried not only about staying warm, but the increased energy costs associated with the extreme cold.  Here are some tips that will ensure your home or business remains warm, and keeps your energy bills low, despite the frigid cold temperatures.

  1. Get a tune up.  The best defense against heating problems is to make sure your system is maintained year-round.  Having heating equipment serviced once before the heating season and once before the cooling season can reduce your heating bill and prevent costly repairs, breakdowns, and ensure your system is operating at peak efficiency.
  2. Clean/change the filters.  Dirty air filters reduce your system's efficiency and thus can cause your system to work harder.  Replace air filters regularly a minimum of every 3 months - and do not block air inlets or outlets with furniture or drapes that restrict proper airflow.
  3. Use a humidifier.  During cold weather, increased use of your heater causes the home and its interior air to become dryer than usual.  A humidifier can help add needed moisture, and can also improve health issues like dry sinuses, while saving energy.  Since moist air holds heat, you may feel more comfortable at a lower heat setting.  Be sure you maintain the humidifier properly: clean or replace the filters regularly and wash the base and reservoir.
  4. Resist using the fireplace unless it's an emergency.  Fireplaces can waste a lot of energy, as they pull warm air out of the house and force it out through the chimney.  Make sure the damper is closed when you're not using your fireplace.  Installing glass doors can also help keep heat in your home when the fireplace is not in use.
  5. Use exhaust fans sparingly.  You lose heated air through exhaust fans, so turn them off when not in use during colder weather.  Not only do they pull heated air out of your house, but they can also cause negative pressure inside your home that can lead to back drafts from your fireplace and can cause drafts through the walls, windows and un-insulated outlets in your home.
  6. Prevent the drain line from freezing.  If you have a high efficiency furnace, there is a drain line that runs from the unit to the outside or into some kind of drain.  Know where that line is and make sure it is protected from freezing.  A frozen or plugged up drain line will cause your furnace to shut down.  If it does freeze, thaw it out (use a hair dryer, never an open flame!), turn off the breaker to your furnace, and turn it back on again to reset it.  It should fire back up.  If you see water around your furnace, chances are the drain line is plugged up at some point, and must be cleared.  Check out our previous post about condensate drainage here.
  7. Address non-HVAC-related air flow issues.  Close up any drafts, seal gaps and cracks around windows and doors (good weather-stripping or caulking usually does the trick), replace old windows or install window insulation kits, and look for places where heat may be escaping and/or cold air is rushing in.  Lack of adequate attic insulation is the main reason heating bills can climb sky high, so extra attic insulation is a good investment.
  8. Take advantage of natural heating.  On sunny days, adjust blinds so they are open and tilted toward the ceiling, but be sure to close the blinds at sundown.
  9. Be prepared for power loss.  In extreme cold, the power grid can get overloaded, and winter weather (snow and ice) can bring down tree limbs and cut power lines.  Keep candles, matches, blankets, flashlights, and a battery-powered radio handy.  When utilizing alternate heating sources, such as your fireplace or wood stove, take the necessary safety precautions.  Keep a fire extinguisher handy and test smoke alarms and carbon monoxide (CO) detectors.  Never run the fireplace without first opening the damper!
  10. Give the HVAC unit breathing space.  Do not store anything too close to your indoor HVAC equipment, and definitely do not store anything flammable - paint, paint thinners, rags, glues, gasoline, cleaning solvents, and other chemicals - near your gas furnace or gas water heater.  Not only is it a safety hazard, but HVAC systems need air in order to burn properly and to draft, or carry the harmful by-products of combustion out the flue.  So, remove the clutter.
  11. If you are going away for an extended time, don't switch the heat off!  Leave it on a low setting to ensure nothing freezes.  Water pipes that break from being frozen cause major damage.  Have a neighbor check on your home while you're gone.
  12. Carbon monoxide is deadly.  One of the biggest threats from the cold is carbon monoxide poisoning.  Carbon monoxide is an odorless, colorless gas that can kill quickly if it builds up in a home.  Symptoms are nausea, headaches and disorientation.  Carbon monoxide is produced by heating systems as a by-product of combustion.  Make sure your heating system is properly ventilated.  If you are heating up your car in the garage, make sure the garage door is open and close any access to your home.  If you find yourself stranded in your car, make sure your tailpipe is clear of snow, or the carbon monoxide can flow back into your car.  

Posted on 02/18/2015 7:00 PM by Eddie Hutton
Sunday, 15 February 2015

Are some rooms in your home too warm or too cold?  Does one floor of your house get much warmer or cooler than the other?  Do you find that some vents blow lots of air while others - usually those farthest from the HVAC source - hardly blow much air at all?  No matter how you set your thermostat, does it seem there is always one (or more) room(s) of your house that don't seem to get to the desired temperature? What can be done?

Special fans can help move more of the heated or cooled air already present in the ductwork into the desired room.  Fans on or in the ducts pull this conditioned air into the room, keeping it comfortable longer, so your furnace or air conditioner will run less often, lowering your utility bills.  But do they work?   


Register Fans

Register fans also called in-floor booster fans are small fans that sit directly in or on the register(s) in the problem room(s).  A few kinds are pictured here.  They are easy to install and inexpensive usually less than $80 each. Some come in different colors, have their own thermostat, are multi-speed, or can be electronically controlled.  Most users of register fans find them noisy and prone to frequent failures/burnout.  They can also be a bit cumbersome since they have an electrical cord that needs to be plugged in (wires dangling across the room).  Most of these small fans are akin to the fan inside the typical desktop computer, and they are not rated with a high enough airflow (cfm cubic feet per minute) to really make a difference.  Some believe register fans further restrict airflow because the vent is now blocked by fans.  However, a few folks have found this simple solution helps.  At least it's not too expensive to find out.  


Mid-Duct Fan

A good alternative is installing a mid-duct fan also called an inline duct fan.  This is a large, heavy-duty cylindrical fan, taking up the entire width of the ductwork, e.g., they "replace" a section of ductwork. They are placed mid-way between the HVAC source and your problem room(s).   Your HVAC ducting must be accessible and exposed to install and work on it.  They require an electrical outlet or they can be hardwired, and require a relay back to the furnace.  So, you'll need an electrician or HVAC professional for installation.  Inline duct fans are quieter than register booster fans, and cost $30-$150 each, depending on the size (note: you need to know the size and shape of your existing ductwork so you can pick the right-sized unit!), cfm rating, and features, plus a couple hundred dollars for the electrician.  


Uneven Heating & Cooling

The solutions described above may fix the symptom of uneven heating and cooling, but it is always best to address the root cause of the problem.  Here are some of the typical things that may contribute to airflow problems:

  • clogged air filters,
  • air vents or dampers which are blocked by furniture or not opened fully,
  • return air registers that are blocked, cracks/leaks in windows and doors,
  • a dirty blower wheel and/or coil,
  • leaks in the ducts themselves due to peeling duct tape or holes made by plumbing or rodents. 

If none of the above things is the source of the problem, you might need to address the problem in another fashion.

Often the biggest challenge is the return air - getting the stale air from the second or third floor back down to the furnace to be heated or cooled and redistributed.  In these cases, the best solution is adding returns or installing a thermostatically controlled zone system. 

Having your air duct system professionally balanced might solve the problem and will improve comfort and efficiency.  But if your problem is due to poorly insulated rooms, or undersized ductwork, then no amount of balancing will fix the problem.


The bottom line is that the lack of proper airflow drastically reduces the efficiency of your heating and air conditioning system. Poor airflow decreases system performance, raises utility bills, and reduces equipment life.  It is best to find the root cause of the problem and address it.

Posted on 02/15/2015 8:13 AM by Tony Anderson
Saturday, 31 January 2015

Tony Anderson, Partner, discusses the new federal goverment regulations for home HVAC systems.

Effective January 1, 2015 all manufacturers of HVAC equipment can no longer manufacture 13 SEER equipment meaning that you can only buy a complete system with a 14 SEER or better rating.  Commercial HVAC systems are not subject to this regulation.

The repair on any piece of equipment is a personal decision. For example if you are going to stay in your home for the next five years and your eight-year-old 13 SEER HVAC, which uses the phased-out R22 refrigerant, needed a new blower motor, you may want to do that repair.  If you're only going to be there a year or two, for sure you'll want to repair it, rather than replace it.  But if you are going to be there for the long haul (10-15 years), you may consider replacing it with a new 14 SEER system that uses the new R410 refrigerant. You'll get many better features: these newer systems are quieter, they have better blower motors, and the the whole works (compressor, bearings, etc.) are built better with higher efficiencies.

People ask why are we doing this?  It's just like your car. Every time you look at the gas mileage ratings on cars, it continues to get better and better.  That didn't naturally happen; it's mandated by the government.  Same thing in our industry. Heating and air conditioning equipment would have remained at an 8 SEER rating if something better hadn't been mandated.  Just during my career, the industry has gone from an 8 SEER to 10, 12, 13 and now we are at 14 as the minimum.  Check the yellow tags that come on your equipment to learn what the SEER rating is. These new regulations are good for the consumer because they mean lower utility bills, good for our industry because it forces continual innovation, and they are good for our environment because they consume less energy and deplete the ozone less while providing the same or better comfort level.

Posted on 01/31/2015 10:03 PM by Tony Anderson
Thursday, 15 January 2015

Something is not working quite right.  All you know is that it's cold and your heat does not seem to be working as it should.    Listed below are some common issues, their common causes, and tips on how you may be able to fix the problem yourself, before contacting a service technician for repair.  This can save you time and money. 


1.   Filter-related Issues

  • Dirty filters are the most common cause of heating (and cooling!) problems because they restrict airflow.  When the filter is clogged and the system can't "breathe," the heat exchanger will overheat and shut off too quickly, and your house won't warm up. It also causes the blower to run hard and for long periods of time, with little heat coming out, and could shorten its lifespan.  Dirty filters also cause soot buildup in the system, reduces your system's efficiency (thus costing you more money to operate), and shortens its life.  This is an easy solution: replace all filters. Be sure to check for the correct size (they are sold by size, not manufacturer).  Get the highest-rated ones you can afford to get the best indoor air quality and performance.  Important tip:  When you replace the filters, make sure the arrows on the filter are pointing towards the furnace (away from you).  Never try to skimp by vacuuming and re-using filters.
  • Listen for a whistling sound.  This is a sign that the system is not getting enough air, due to a clogged filter or obstructed airflow.  If you've already changed the filters and still hear the whistle, then there may be an obstruction elsewhere in the system. Check to make sure all the registers are open and unblocked.

2.   Thermostat-related Issues  

  • If the display on your thermostat is blank, it could be there is no power to the thermostat.  A tripped circuit breaker or fuse could be the problem, possibly caused by a power outage, power surge, lightning strike, or storm. Reset the tripped circuit breaker or replace the fuse. Make sure all the wires going to the thermostat are connected and not loose.  Useful tip: If you've lost your owner's manual for your thermostat, most major-brand manuals can be found on the web-just go to the manufacturer's web site.
  • Check that the thermostat is in heat mode. If it's a programmable thermostat, switch it to manual control and set it for 5 degrees above the room temperature, and wait to see if the heat cycles on.   For programmable thermostats, check that it is set to the correct day and time (am or pm). 
  • If your thermostat is battery-powered, or relies on battery for backup power in case of a power outage, it could be that the battery needs replacing.  If you have a programmable thermostat, and had a recent power outage, it could be that without a functioning battery backup, all of your settings have been wiped out by the power outage and the thermostat reverted to its default program. 
  • If your thermostat has a switch to control the furnace fan, switch the fan "On" (as opposed to "Auto" or "Off").  If you do not hear the fan coming on, go to one of the supply registers and see if you can feel any air coming out. If the fan is not running, there may be no power to the furnace.  If the fan runs, but the air coming out is cold, you have a problem with the furnace (or heat pump) itself.

3.   Electrical-related Issues

  • Check to see if the circuit breaker or fuse controlling the heating system is tripped or blown.  If a breaker has been tripped it will be in a position that is between ON and OFF. Reset the breaker by turning it all the way OFF, then back ON. If your home has fuses, check to see if the fuse for the furnace is blown. If so, replace it with the same size and type of fuse. Do not increase the size of the fuse. Important Tip:  If a breaker keeps tripping or a fuse keeps blowing, contact a qualified service technician to inspect your system to determine why you are having problems.
  • Check to see if the switch located near the heating unit is switched on.  This often looks similar to a light switch and easy to mistakenly turn off.  (In one house, the switch was mounted upside down, so the unit was actually "on" when the switch was in the "down" position!).  Useful tip: Most thermostats get their power from the same electrical circuit that feeds the HVAC system.  So, if your thermostat is not responding, turning on the switch by the HVAC may be the solution!

4.    Furnace-related Issues

  • Check to see if the pilot lot has gone out (if your furnace has non-electric ignition).  The solution is to relight the pilot light.  If you are unsure how to this, contact your gas service provider.  If the pilot will not light or stay lit, call a service technician.
  • Most furnaces today have electronic ignition switches rather than a pilot light.  If that gets stuck, try switching the furnace off, wait a minute, then switch it back on. If your furnace has a reset switch, press it. After another minute, you should hear the furnace fire up.
  • Make sure the gas is turned on.  Trace the gas line back from the furnace to the meter, and if there is a handle that's perpendicular to the gas pipe, turn it so it's parallel. There should be no obstructions or kinks in the gas line. Also, if you have other gas appliances and they are all working, then you know the gas line is on and not obstructed.
  • Some furnaces have emergency cut-off switches that are activated when a door or service panel is removed. If the furnace door is not closed properly (such as after a filter cleaning, or accidentally bumped open), the cut-off switch will prevent the furnace from coming on.  Check to make sure all access doors are properly closed and secured.
  • Make sure the exhaust line or flue is clear.  I'm not talking about the chimney flue in your fireplace, but the part of your furnace that exhausts to the outside, usually through a metal duct.  Sometimes birds, drawn by the warmth, build nests in it.  To clean it, you'll need to turn off the furnace first.
  • High-efficiency furnaces can drain off several gallons of water a day during the heating season. If the drain lines become restricted by sediment or mold growth, the furnace will shut down. If the drain line is in unconditioned space, and the water in the line freezes, that, too, will cause the system to shut down.  Check the drain hose, and if it looks dirty, remove it and clean it with a mixture of 25% bleach + 75% water, and after flushing it for several minutes, replace the hose.

5.   Heat Pump-related Issues 

  • Check to see if the outdoor unit is covered in ice. It is normal for the coils to frost-over, especially if there is lots of moisture in the air (mist, rain, or sleet).  Your heat pump has a defrost cycle that normally melts this frost.  However, if the ice on the coils is extremely thick, never seems to melt, and only seems to get worse with time, then there could be a problem with the defrost cycle.  Try switching the system to "Emergency Heat" at the thermostat. Wait until the sun melts the ice off, then try turning the system back to "Heat."  If you do not hear the heat come on, or if you hear loud noises, turn the system back to "Emergency Heat" (thereby shutting off the outdoor unit) and call for service.
  • When outdoor temperatures stay below about 35 degrees, it is normal for the backup or auxiliary heat light (usually a blue or green light) to come on. The colder the temperatures, the longer this light will stay on. But if the light comes on and stays on, even when outdoor temperatures rise above 35-40 degrees, then there is a problem with your outdoor unit and you'll need to call for service.
  • Clean away leaves and debris around the outside unit that could be restricting the airflow.  Be sure the outside unit is not covered if you are trying to use it!


Never fear.  If none of these fixes your problem, we're always here to help!

Posted on 01/15/2015 7:28 AM by Tony Anderson
Thursday, 01 January 2015

Jeff Owens, Project Manager, describes the major project at Brentwood Middle School that installed a green, ductless, HVAC system expected to save 25%-30% of the energy previously required to heat and cool a large school building.



Brentwood Middle School opened in August 1972.  It's a large school with 1,250 students in grades 6 through 8. In 2014, it was named by thebestschools.org as one of the top 30 schools in theO USA.  Learning can be hampered by environments where students are distracted by noise, or in temperatures that are too hot or too cold. In 2013, it was decided that the 41-year-old school should replace its antiquated HVAC system.  They chose a system that would need no ducts for conditioned hot and cool air, would keep classrooms quiet, would let teachers control their individual classroom's temperature, and would use no floor space for equipment.  The project required removing all the ceiling tiles, all lighting, all the old ductwork, all floor-mounted air handlers, and all roof-mounted equipment.  The work was done during two summer breaks so there was no need to close any classrooms.  

Mitsubishi VRF

The system uses  a Mitsubishi VRF (Variable Refrigerant Flow) system. In each of the classrooms we have a ceiling cassette that takes care of this particular room and it's thermostatically controlled by a white thermostat on the wall. The teacher can control the temperature in each room. Before there was one central thermostat controlling all the rooms.


This is called a ductless system and you have no ductwork above the ceiling and you have four directional blowers with air flowing in four different directions in the classroom. There are approximately 74 units throughout the building.  Another good feature for these Mitsubishis is that they're quiet - only 30-35 decibels. You can't even hear the thing running in the classroom. It is very quiet unlike a conventional system. Each cassette is connected to a condensing unit on the roof. There are eight condensing units on the roof and each feeds 15-20 air handlers. There is a flow of refrigerant and as the system requires heating or cooling it will flow the refrigerant needed to heat or cool a particular room.  This is a two-ton capacity unit so it can use as much as 24,000 BTUs of refrigerant.

Fresh Air

 Of course there has to be a way to bring fresh outside air into each classroom and that does require ducts and vents.  Reznor make-up units on the roof filter the air, and blowers pump the air to the vents. There are no return air ducts. The fresh air pumped in by the make-up units result in the rooms having a positive air pressure, which then exits through leaks around windows and doors.  There are five makeup air units on the roof that condition the outside air. 100% outside air goes in and is heated or cooled as required and then is directed into each classroom.

Energy Savings

 As the sun comes up in the morning, one side of the building requires cooling while the other side does not. An energy management system determines which of the eight condensing units to run.  This saves energy. The energy used is being measured by the energy management system and is expected to be 25 to 30% less than the old system.  Data from the old system has been retained and in a year we should be able to report exact figures.

Posted on 01/01/2015 1:10 AM by Tony Anderson
Thursday, 18 December 2014

On a cold morning, just the thought of having your feet hit a cold floor makes you want to stay in bed! With radiant floor heat, even your dog will want to curl up on the bare floor rather than in your bed.  Radiant heat has benefits when compared with traditional convection heat. But what is it and how does it work?

Radiant heat elements in the floor, wall or ceiling warm the people and objects in the room rather than directly heating the air. You cannot see radiant heat energy but you can certainly feel it, and it just makes you feel more comfortable and cozy.  It works like sunshine.  When you're outside on a sunny day, you may feel comfortable in short sleeves even if the air temperature is only 60 degrees. This is because of the radiant warmth from the sun.  Radiant heat lets you feel warm at a lower air temperature than conventional forced-air heat.  Plus, because there is no blower as with forced-air heat, there are no drafts.

Energy Efficient

It is estimated that radiant heat is not only about 30% more efficient than conventional forced-air systems, but provides a more even and continuous level of warmth.  Here's why:

  • With radiant heating, the heating elements are near you in the floor or walls.  No ductwork is needed as part of the delivery system, and ducts are where some heat is lost. 
  • Since radiant heating systems do not use blowers or fans, your environment stays quieter.
  • With radiant systems, heat stays near the floor where you are, and is not collecting near the ceiling.
  • Radiant systems easily provide room-by-room temperature control, or multiple separate zones, allowing more heat where you want it most.

Other Benefits

Besides saving energy, here are some other benefits of radiant heat:

  • Health benefits: European studies indicate that dust mite populations are reduced as much as 90% in radiant heated homes.
  • No humidification needed: Unlike hot air systems, radiant heat will not dry out your breathing passages.  Humidification is unnecessary with radiant heat because it does not alter the air moisture content.
  • Environmentally friendly: Radiant systems can run off of a variety of energy sources (gas, oil, wood, etc.), and can easily be interfaced to solar, geothermal, and other renewable energy sources. [For more information on environmentally-friendly systems, check out our LEED story.]
  • Flexibility: Radiant floor heating systems can be installed under any type of flooring, including wood, tile, laminate, concrete and carpet. Beautiful wood, marble or tile floors are even more enjoyable because they are now warm, and don't need to be covered up with rugs to shield bare feet from a cold floor.
  • New construction or remodel:  Radiant heating can be customized for rooms of any shape or size, and can convert cold, damp areas into warm living space.  Add radiant floor heat in large lower-level rooms or basements that are almost uninhabitable during winter months, or a garage space being converted into living space. It works really well in a concrete slab, too.

Many Types

There are many types of radiant heating systems. 

  • Under the floor or in the walls:  These are called low-temperature systems.  Since their heating surface is much larger, a much lower temperature is required to achieve the same level of heat transfer.
  • Radiant heating mats: These are ideal for spot heating, like shower floors or benches, and are safe for wet location installations.
  • Radiant heating room panels:  These can be hung on the wall (like artwork) and typically are glass or mirrored, and come in a variety of colors and sizes.
  • Overhead panels:  These have a lot higher surface temperatures, and can be found in production and warehousing facilities or sports arenas.  They boast the quickest response time of any heating technology.
  • Radiant heat can be used outdoors as well.  In cold climates, some folks have heated driveways or roofs so they don't need to shovel snow or worry about the snow pack causing the roof to collapse.

There are two basic ways to supply radiant heat in floors or walls: hot water or electricity.  Electric radiant, which uses zig-zag loops of resistance wire, is ­generally retrofitted to a single room, such as a bathroom, kitchen, or added room, such as a converted garage. It can be used for spot installations and operate along with traditional forced-air heating systems used in the rest of the house. Hot-water "hydronic" systems circulate water from a boiler or water heater through loops of 1/2-inch flexible plastic tubing.  Hydronic systems are better suited for whole-house (rather than spot) installations.

What About Air-Conditioning?

Keep in mind, no matter what radiant heating system you use, you'll still need a separate air-conditioning system for cooling.  Radiant cooling cannot be used in Tennessee because our high humidity would cause excessive condensation (not a problem for heating systems).  That means that although radiant heat does not use ductwork, registers or vents for heat delivery, you'll likely still need these for a cooling system.

But with radiant heat, you can say goodbye to cold floors in winter! Radiant heating can be a comfortable, efficient, and reliable heating choice.

Posted on 12/18/2014 3:01 AM by Tony Anderson
Monday, 01 December 2014

Eddie Hutton had this video produced to help homeowners learn how to save energy, improve the environment  and make older homes go "green."

Saving energy and helping the environment that's what the U.S. Green Building Council (USGBC) is all about. They developed the LEED green building certification and rating system.    LEED is an acronym for Leadership in Energy and Environmental Design.  The LEED ratings describe the degree to which a building reduces negative environmental impacts and improves the health and well-being of its occupants. There are four rating levels based on the number of points achieved: from Certified (which starts at 40 points), to Silver, Gold, and Platinum (which requires a score of 80 or more points).

LEED-H is the rating system used for homes.  There are many categories outlined in a scorecard, such as:

  • Location and Transportation: This includes proximity to a variety of transportation options, like bicycle paths and mass transit.
  • Sustainable Sites: This includes rainwater management, using natural land cover, and protecting nearby habitat.
  • Water Efficiency:  This includes reducing both indoor and outdoor water use, and tracking water consumption via water metering.
  • Energy and Atmosphere: This includes refrigerant management, energy metering, and optimizing energy performance by using renewable energy sources.
  • Material and Resources: This relates to the construction techniques, which must make use of environmentally-certified or recycled building products, sourcing raw materials locally or regionally, and reducing the amount of waste stored in landfills.
  • Indoor Environmental Quality: This covers things that affect air quality, lighting quality, acoustic design, and surroundings, such as ventilation, low-emitting materials, and making use of natural lighting and heating.

The scorecard also rewards things like innovation, adaptability, and regional (geographic) priority areas. 

Is your home a candidate for renovation and a LEED-rating?  You know, LEED is not just for new construction!  Maybe you want to start small.  Perhaps your home has a detached garage you'd like to renovate to be used as a vacation rental.  After all, we hear that Nashville is a destination site for many travelers! Having a Platinum LEED rating would sure serve as a differentiator when marketing your rental!

Let's look at ways a house could attain a LEED rating.  First is its location: ideally, it would be in a neighborhood with bicycle paths and an MTA bus route, and close to parks, downtown and shopping. Add a geothermal heat pump for the HVAC system.  That way you can use a desuperheater to capture waste heat to provide hot water.  LED lighting is an ideal way to reduce energy consumption because LED lights use only about 1/5th the power of incandescent lights, so the payback interval is shorter than any other energy saving approach. Plus, since LEDs don't radiate heat like typical incandescent bulbs, they reduce the load on the home's air-conditioning system.  Insulation is also very important in reducing the cooling and heating costs.  The best product out now is a soy-based spray foam insulation, which is not only eco-friendly, but is resistant to air, rodents, insects, mold, mildew, moisture and reduces sound transfer.

Download a copy of the LEED Scorecard and start your Green Home project today!

Posted on 12/01/2014 6:00 AM by Eddie Hutton
Saturday, 15 November 2014

It is easy to be overwhelmed with the many different thermostats on the market and all the features!  Which one is right for you?  We've taken three of the top thermostats and done a comparison for you: the Honeywell WiFi, the Nest (now owned by Google), and the Honeywell Lyric. All tout easy installation and setup, and all allow you to control the thermostat remotely from a smartphone via a free downloadable app.  All will save you money on your utility bills if used appropriately.  Each of these thermostats uses different programming methods - or better said, what triggers the change in temperature settings - is quite different among the three.  So, depending on your habits, one might be better for you than another.

Honeywell WiFi

User ratings of this thermostat are very high, and higher than the user ratings of the Honeywell Lyric and Nest in most cases.  Users like the smartphone app a lot, and you can operate it from a website, too. You can schedule temperature changes for waking, leaving, returning, and sleeping.  Programming is a matter of setting up a 7-day schedule for each of these changes.  You can override the schedule at any point, but this method works well if you have a fairly predictable schedule most of the time. Temperature control is spot on, within +/- 1 degree. The touchscreen wall unit offers a multitude of preferences: colors, displays (Fahrenheit/Celsius, 12/24 hr. time, temp/humidity, etc.), brightness, auto/manual, keypad lockout, hold temperature option, and much more.  Plus, there is a smart mode whereby it learns how long it takes to reach a desired temperature and proactively adjusts, and it reminds you when it's time to change your filters. The cons were few:  If your internet connectivity is down, you can only control the thermostat from the wall unit (same as a traditional thermostat), your color preferences cannot be saved, and circulate mode (fan) is preset at 35%.  Depending on the retailer, the cost for this unit varies from $193-$230 (not including installation).

Google Nest 

By comparison to the Honeywell WiFi, the Nest is more simplistic. The display only offers temperature, and not the multitude of preferences (colors, etc.) like the WiFi does.  Also, unlike the WiFi, you cannot do all the functions from the thermostat wall unit that you can do from your smartphone. There is no hold temperature option, and the temperature control was only +/- 3 degrees (a 6 degree swing is enough to make it feel too hot or too cold). Like the WiFi, it learns how long it takes to heat up and cool down to your set temperatures and proactively adjusts.  There is no need to enter a 7-day program, though you may.  You can merely set target home and away temperatures (for cooling and heating) for a single day or week, and it uses that as a starting point.  Then, the Nest "learns" your patterns by having a sensor that senses when someone is home.  So, if you have an erratic schedule, this feature might be ideal.  However, user reviews say if you have a big house, its line of sight will not cover the entire house, so you may be home but in another room where the sensor can't sense you, and thus the "away" mode kicks in.  Many users found the "learning" was imprecise at times, and some gave up on it and opted for straight programming of temps at specific times.  The thermostat is accessible via the internet and the unit itself maintains connection to an internet website to tell you the outdoor temperature.  Nest offers usage reports and shows you, via a green leaf on the display, when you're saving energy.  Users reported many frustrations, including software updates that wipe out your settings and any "learning" that was done, and time changes (for Daylight Saving Time) did not update the temperature settings, but many problems have since been fixed in newer updates. The Nest's construction is solid (glass and stainless steel vs. the Honeywell's plastic) and costs for the "second generation" of Nest units vary from $249-$300 (not including installation).

Honeywell Lyric

The design of this unit at least on its face is similar to the simplistic display of the Nest.  But its geofencing feature represents a totally different programming alternative. It uses your smartphone's location to determine whether you are home or away, and sets the temperature accordingly.  If you're the type of person that doesn't go anywhere without your smartphone, this might be for you, but be aware that everyone in the household must have the app installed on their smartphone.  Multiple thermostats can be controlled from the same app.  Users say the Lyric does a better job than the Nest at fine-tuning the temperature: it considers both indoor and outdoor temperature and humidity to reach a set point. Users found the software app with the Lyric more clunky than the Nest, and some functions can only be done from the smartphone or web, not from the wall unit. Many reviewers reported the geofencing was not reliable, problems working with iOS 8, multiple manual resets when internet connection was lost, and other frustrations causing them to set up shortcuts or do manual overrides or to swap out the unit due to frequent breakdowns.  Others reported poor experiences with Honeywell's customer support, or that they did not like the wobbly plastic feel of the device.  As with the Nest, there is both an older and newer model, plus there is a retail and contractor's version.  Costs for the newer retail model range from $219-$280 (not including installation).

With all smart thermostats, you'll want to check compatibility with your home's HVAC system before purchasing one.  Some do not work with baseboard heat, for example, and if you have multiple zones in your house, you'll need multiple thermostats.  Installation can be done by the homeowner, but know that we are happy to help you install any thermostat of your choosing.  

Posted on 11/15/2014 8:06 AM by Tony Anderson
Friday, 31 October 2014

In August, we began our Smart Thermostat Poll to get your input on some of the features manufacturers are now offering on their new crop of thermostats.  Are manufacturer's over-engineering these or are these really features people want?  We put it to the test, by asking which features you liked or thought you might use (a "yes" answer) and which features you either didn't care about or wouldn't use (a "no" answer).  Here's a summary of the results*:

The features most users said they wanted or would use are:

  • Reminders to change your air filters.
  • Allowing you to override your "normal routine" when on vacation (away mode).
  • Alerting you when the temperature in your home gets too cold or too hot, which may mean your HVAC unit isn't working.
  • Allow you to run only the fan (to circulate air) without having to run the air conditioner or the heat.
  • Having the thermostat derive its power from your HVAC (instead of running on batteries).
  • Automatically adjusting for daylight savings time.
  • Automatically downloading software updates from the Internet.

Features users said they would be least likely to use were:

  • Having a portable (handheld) thermostat control that can be used in any room of the house.
  • Having the display in different languages.
  • Being able to upload a photo that displays on the thermostat's screen, with screen saver and slideshow features.

Thank you to all who have already taken the poll.  If you haven't taken the poll yet, there's still time (click here)!  Plus, just for taking the poll, we'll send you a coupon good for 10% off the installation of any thermostat of your choice. Enter your name and email address at the bottom of the poll.  To be eligible your home must be in Davidson, Williamson, Rutherford, Wilson, Sumner or Cheatham counties.

With all the different models, prices, and features, and 10% off installation, what's YOUR excuse for not saving energy and money?

* If you'd like the detailed results (all categories with percentages of responses), subscribe to our blog and we'll email the detailed results to you.

Posted on 10/31/2014 4:39 AM by Tony Anderson

Important Tips & Advice



You often don't think about your heating or air-conditioning system until something goes wrong. But there is so much you can do to help keep your system from breaking down. We regularly post information to help you learn what you can do to keep your system running, to save money and energy.  Search our many posts, videos, and podcasts, for valuable information that is never a sales pitch. Subscribe to receive an email when something new is posted, so you won’t miss any important tips.

Choosing a Repair Company

Whether you’re talking about heating or cooling, repairing or replacing a system, you want a company that can advise you reliably based on what is in your best interest, not based on what is convenient or what earns them the most money (commissions). We'll help you choose the best solution to fit your needs. Check out our many posts at HVAC News You Can Use and our podcasts.

Going Green

We're concerned about the environment and know all the latest technologies - such as geothermal systems, LED lights, and smart thermostats - that can reduce energy and put more "green" in your pocket!  We've provided HVAC systems in certified LEED buildings and written many posts on ways to Go Green.

The Sign of Service

We are a repair company performing a full range of commercial and residential heating, air conditioning, energy management and comfort products service, maintenance, and installation. We are a locally-owned company serving Nashville-Davidson County and the surrounding counties including Williamson, Rutherford, Wilson, Sumner, Robertson, and Cheatham.

Who We Are

Our service technicians are fully trained and experienced.  We can tackle the most complicated system to the simplest of systems – from large commercial plants to single-family homes.  Our ownership group of Eddie Hutton, Tony Anderson, Roger Eldridge,  Swaney Powers and Alan Seilbeck have over 125 years combined experience as leaders in the HVAC industry.


We are proud of our dispatchers that respond to your telephone call. When your system is down they make things happen. Our trucks are loaded with most parts needed for a quick repair. You can call day and night 7 days a week. Our normal weekday hours are 7:00AM to 5:00PM. Click on the button below to schedule a service call online. Emails and forms can only be answered weekdays from 7-5.”  

615-832-8500 Online Service Call


Did you know you should service your HVAC on a regular schedule – just like you would your car?  We have specialized maintenance programs to ensure the clean, energy efficient and safe operation of your HVAC systems.  This helps minimize service interruptions/breakdowns and maximize your equipment's lifespan.  All maintenance contract customers are assigned a primary technician that will get to know your facility and equipment and will treat it like his own.  You’ll receive discounts on repairs or new installations, and get priority service when it is cold or hot outside and you need service promptly.  Plus, maintenance contract customers are never charged overtime rates for emergency services after-hours, weekends or holidays. We’ll teach you how to save on maintenance costs by showing you things you can do yourself and when you need a technician. Here are some good posts:  Repair vs. Replace, Things to Try Before Calling for Service, Springtime Tips that Pay Off.


Our team takes on HVAC projects for office, school, retail and industrial facilities. Check out these case studies:

Replacement of a 250-ton Cooling Tower

Ductless HVAC at Brentwood Middle School