With the San Joaquin Valley’s blazing summer nearly upon us, if you’re looking for an air conditioning upgrade, you’ll need to know how to compare the energy efficiency of different models. Most people think the SEER (seasonal energy efficiency ratio) is the best way to make a comparison. But increasingly, in climates with hot summers, EER is becoming the better standard for comparison. So when it comes to SEER versus EER, go with the latter number.
Laboratories test the SEER efficiency of air conditioners and heat pumps by running them at a fixed “outdoor” temperature of 82 degrees, with the “indoor” temperature set at 80 degrees with 50 percent humidity. In our climate, though, the daily average high temperature is well over 82 degrees from May through September.
EER, however, shows how the cooling equipment performs under hotter temperatures. EER is determined by heating air to 95 degrees, with an interior temperature setting of 80 degrees with 50 percent humidity. The testing equipment measures how much electricity the appliance uses and divides it into the BTUs (British thermal units) of cooling produced over the course of an hour. Engineers divide the watts the appliance consumed into the total BTUs of cooling, to come up with the EER rating.
While the federal government requires all new central air conditioners to meet efficiency requirements for SEER, with the minimum 13 showing on the label, it doesn’t require manufacturers or retailers to indicate the EER. In our hot climate, however, the EER is a better measure of efficiency because of the temperature extremes between outdoor and indoor air, which the EER provides. The higher the number the better.
When assessing new air conditioning equipment, comparing the SEER versus EER is an important step. If you’d like to learn more about the difference and how it can help you lower cooling costs, contact Donald P. Dick Air Conditioning. We’ve servedthe Fresno area since 1970.
Our goal is to help educate our customers about energy and home comfort issues (specific to HVAC systems). For more information about SEER versus EER and other HVAC topics, download our free Home Comfort Resource guide.