The Differences Between SEER & EER


Since the oil crisis in the 1970s, the efficiency of heating and air conditioning systems has been closely scrutinized. Manufacturers have gone to great lengths to design systems that are as efficient as possible. SEER and EER were developed to provide consumers with a method of comparing the performance of different air conditioning systems.


  • 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.


  • 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.

Related Searches


  • Photo Credit Jupiterimages/ Images
Promoted By Zergnet


You May Also Like

  • What Are the Highest Efficiency Heat Pumps?

    Heat pumps are highly efficient systems for heating and cooling a home, especially in areas that have moderate needs for heating and...

  • How to Understand EER & SEER

    Under a climate of uncertain energy security and widespread air pollution, understanding the environmentally apt ratings of EER and SEER is as...

  • How to Calculate EER

    Working out at the gym, digesting food and even sleeping are activities that require energy in the form of calories. The amount...

Related Searches

Check It Out

22 DIY Ways to Update Your Home on a Small Budget

Is DIY in your DNA? Become part of our maker community.
Submit Your Work!