The Differences Between SEER & EER

SEER

• Seasonal energy efficiency ratio (SEER) is the ratio of the total cooling power over a year to the total electrical input over a year. This calculation was developed to provide consumers with a more realistic measure of real-world performance. The total cooling power is measured in BTUs (Britsh thermal units), and that is divided by the total electrical consumption measured in watt-hours. The result is the SEER for the appliance. SEER was developed by the U.S. Department of Energy to give consumers a better indicator of average seasonal performance.

EER

• Energy efficiency ratio (EER) is the ratio of the total cooling power in BTUs to total electrical input in watt-hours at a given operating point. It is measured when the interior temperature of the home is 80 degrees Fahrenheit, the outdoor temperature is 95 degrees Fahrenheit and the unit has had a chance to reach its ideal operation point. This is a measure of the steady-state efficiency of the air conditioner. EER was developed by the Air Conditioning, Heating and Refrigeration Institute (AHRI) and is the original method to compare air conditioner performance.

SEER and ERR Differences

• The main difference between SEER and EER is that SEER is a measure of efficiency over a full season, while EER is a measure of performance at a given moment. Both are calculated in similar methods and provide a way to compare air conditioner efficiency. Since SEER has been developed, it has become the standard tool for measuring performance in residential air conditioners.

Air Conditioner Efficiency

• A typical older air conditioner has a SEER rating of 6. More modern units use scroll-type compressors, which have fewer moving parts and thus are both more efficient and have a tendency to break down less. These air conditioners have reached an average SEER rating of around 13. Some manufacturers who are pushing the limits of performance have seen their units reach SEER ratings of 14 or higher. However, the cost of these high-efficiency units may outweigh the gains achieved in saving electricity.