Friday, 14 March 2014
What's Your SEER? Does It Matter?

SEER stands for Seasonal Energy Efficiency Ratio.  This is a rating given to air conditioners that measures their relative efficiency.  The higher the SEER rating, the more efficient the unit is.   To find the SEER of a particular air conditioning unit, the Air Conditioning, Heating, and Refrigeration Institute looks at the cooling output during a typical cooling season divided by the total electric energy input during the same period.  This is measured as the ratio of cooling in British thermal units (BTUs) to the energy consumed in watt-hours.

Does it matter what the SEER rating is of your air conditioner?  It does if you are cost-conscious!  No one wants to see huge electric bills in the summer as the heat and humidity rises here in Tennessee.  The SEER rating can help you compare the cost of operating two seemingly identical units (units having same BTU output).  It lets you spend your money more wisely.  It lets you invest in a unit that will actually save you money because it will cost less to operate.

Comparisons and Standards

One variation of the SEER is the EER, the Energy Efficiency Ratio.  The EER is a more realistic measurement of energy efficiency in warmer climates due to the high demand and higher cost of peak hour electricity.  It is measured as the ratio of output cooling (in BTUs) to input electrical power (in Watts) at a given operating point, usually 95°F and 50% humidity outside.   SEER rating more accurately reflects overall system efficiency on a seasonal basis and EER reflects the system’s energy efficiency at one specific operating condition. Both ratings are useful when choosing products, but the same rating must be used for comparisons. As of January 2006, all residential air conditioners sold in the United States must have a SEER of at least 13, and ENERGY STAR qualified central air conditioners must have a SEER of at least 14. [Note: window units are exempt from this law and their SEERs are only around 10.]   Today, it is rare to see systems rated below SEER 9 in the U.S., and if yours is, you should replace it with a new, higher efficiency unit.  

Savings Can Be Substantial

Substantial energy savings can be obtained from more efficient systems. For example by upgrading from SEER 9 to SEER 13, the power consumption is reduced by 30% which can translate into energy savings up to $300 per year (depending on the cost of electricity).  In 5 years, that comes to an extra $1500 in your pocket without lifting a finger!   And, the longer the cooling season and the longer you keep your system, the more important the SEER rating is to your pocketbook!  Here in Tennessee, the savings can easily be much more because of our long cooling season and high humidity.  This is reflected by the U.S. Dept. of Energy’s elevated minimum standards for split system central air conditioners installed in the Southeastern Region of the U.S. which must be at least 14 SEER starting January 1, 2015.

Choosing a System

Today there are mini-split (ductless) air conditioner units available with SEER ratings in the 25 to 28 range, and geothermal (or ground-source) units may have SEER ratings up to 75.  Even replacing your 10-year-old central air conditioning unit with a new one can save you 30-40% in electricity costs.  And now that the old refrigerants are being phased out, there’s no better time to make a switch!  When choosing a new system, be sure to compare their respective SEERs. 

Posted on 03/14/2014 5:23 PM by Cheryl Austin
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