Friday, 15 February 2013
How Geothermal Works

Roger Eldridge, Partner uses a series of diagrams to explain the basic principles of water source geothermal systems.

A geothermal system  is explained in the following steps.

  1. In small homes 300 ft of horizontal pipes are installed 4 ft underground or a 300 ft vertical well is drilled.  In larger buildings there may be many 300 to 500 ft wells.
  2. The pipes are connected in a loop and sealed. This is the first of three loops.
  3. An electric pump is installed to circulate a mix of water and antifreeze. NO GROUND WATER IS EVER USED IN THE SYSTEM.
  4. The fluid in the loop is heated or cooled to 60° F by the earth.
  5. The heat pump unit is installed inside the building. The refrigerant in a second closed loop is compressed by the compressor.  In cold weather, as the refrigerant goes through the coils it removes heat from the ground loop. After moving through a pressure reducer, the refrigerant gives off heat.
  6.  The supply duct work and a fan or blower are installed and move the heated air through the heat exchanger to the rooms of the building.
  7. The return air ducts are installed and return the air to the blower. This completes a third loop.
  8. When it is hot outside, the compressor is reversed. The 60° F water in the ground loop is now use to cool the coils and via the heat exchanger and ducts cools the inside air.

The US Environmental Protection Agency (EPA) says geothermal heat pumps are among the most efficient and comfortable heating and cooling technologies currently available, because they use the earth’s natural heat to provide heating, cooling, and often, water heating.  Click here for the EPA reports.

Posted on 02/15/2013 2:56 AM by Roger Eldridge
Friday, 1 February 2013
What about Geothermal HVAC for homes

Roger Eldridge, Partner, explains how a geothermal system can save 50% of the energy required to heat and cool a home with conventional systems.

The fact that the earth is always the same temperature year round, the efficiency of the unit is twice what it is with a conventional system so that is where the energy savings is. The efficiency of the system goes up dramatically. A typical heat pump fluctuates efficiency based on the temperature pf the outdoors especially in the winter time. When the temperature goes down, the capacity of the unit decreases until it reaches a point where you get almost nothing out of the system. Geothermal never has that problem. It is always a constant so you are getting the same amount of heat extracted from the earth year round.

Geothermal is a system that uses the earth as a condensing unit. Instead of having a piece of equipment outside of your house it uses the earth as a heat sink. It transfers the energy from heat in the house to the earth and takes energy from the earth to cool the house. It’s a standard heat pump with the only difference it uses wells in the earth as the condensing part of the system instead of the air.

There are two methods; vertical wells and horizontal wells. If you have a 300 foot well four feet under the ground or a vertical well it will provide 2.0 Tons of cooling A 300-500 ft A 300 ft vertical wells will provide the same amount of cooling. You re-circulate water with a mixture of 15% methanol or antifreeze. The earth has a constant temperature always around 60 degrees. The heat pump in the winter time pulls heat from the earth re-circulates it to the heat pump unit where the heat is extracted from the refrigerant and circulated through air. It heats the air up and the air is circulated though the house. In cooling the cycle is reversed. It absorbs heat in the house transfers it to refrigerant, to the water, to the ground, the ground absorbs the heat.

Is auxiliary heat needed with a geothermal system? The only reason we recommend putting any kind of electrical auxiliary heat is purely as emergency backup in case the geothermal heat pump part of the system was to fail so you would not be totally without heat.

Presently until 2016 the Federal Government is offering a 30% tax credit on a primary residence geothermal system which covers the total cost of the installation. I used it myself so I know that for a fact; saved me about $15,000.

The US Environmental Protection Agency (EPA) says geothermal heat pumps are among the most efficient and comfortable heating and cooling technologies currently available, because they use the earth’s natural heat to provide heating, cooling, and often, water heating. Click here for the EPA reports.

Posted on 02/01/2013 1:05 AM by Roger Eldridge

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