Definition
SEER2 (Seasonal Energy Efficiency Ratio 2) rates how efficiently an air conditioner or heat pump cools across a full season, under the updated federal test procedure adopted in 2023. A higher SEER2 means more cooling per kilowatt-hour. It replaced the older SEER metric, so SEER2 numbers run slightly lower than the SEER figures on legacy equipment for the same unit.
Why this matters for your home
When you compare AC quotes, make sure you're comparing SEER2 to SEER2. A higher SEER2 costs more upfront but lowers your summer electric bills — worth weighing against how long you plan to stay in the home and West Michigan's relatively short but humid cooling season.