SEER
Seasonal Energy Efficiency Ratio — the standard rating for cooling efficiency.
Definition
SEER (Seasonal Energy Efficiency Ratio) measures the total cooling output of an air conditioner over a typical cooling season divided by the total electricity input over that season. Higher SEER means more cooling per unit of electricity. Federal minimum SEER for new residential AC is 14 (north) or 15 (south); premium variable-speed units reach 22-26 SEER. SEER2 is the updated test methodology effective 2023, with numbers about 4.5% lower than the old SEER for the same equipment due to a more realistic test profile.
Where this term appears
SEER comes up in product spec sheets, service reports, and troubleshooting documentation across most major appliance brands. If you encountered it in a manual or a service description and want context for how it fits into the larger picture, the related articles in the sidebar drill into the practical details. The glossary as a whole is intended as a quick lookup reference; for a deep dive on any specific topic, jump to the related buying guide or troubleshooting article.