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SEER2

SEER2 is the federal seasonal cooling efficiency rating for air conditioners and heat pumps, in Btu of cooling per watt-hour.

Editorial staffEdited by heatpumpwiki

History 1

SEER2 (Seasonal Energy Efficiency Ratio 2) rates cooling efficiency over a typical cooling season: the total heat removed, in Btu, divided by the electricity used, in watt-hours, under the federal test procedure.Source 1

The federal minimum for split-system heat pumps made on or after January 1, 2023 is 14.3 SEER2.Source 2 Regional minimums in the Southeast and Southwest apply to central air conditioners, not heat pumps.Source 2

SEER2 replaced SEER in 2023. DOE's example: "a unit rated at 15 SEER would be a 14.3 SEER2."Source 3 Compare SEER2 numbers with SEER2 numbers. See EER2 and Heat pump ratings explained: SEER2, EER2, HSPF2 and AHRI certificates.

Sources

  1. 1.10 CFR Appendix M1 to Subpart B of Part 430, Uniform Test Method for Measuring the Energy Consumption of Central Air Conditioners and Heat Pumps. Electronic Code of Federal Regulations (U.S. DOE rule). Accessed Oct 25, 2026
  2. 2.10 CFR 430.32, Energy and water conservation standards and their compliance dates. Electronic Code of Federal Regulations (U.S. DOE rule). Accessed Oct 25, 2026
  3. 3.Air-Source Heat Pumps (archived copy of energy.gov/energysaver/air-source-heat-pumps, captured June 20, 2026). U.S. Department of Energy. Accessed Oct 25, 2026

More in Glossary

  • AHRI certificateAn AHRI certificate shows the certified efficiency ratings for one exact combination of outdoor and indoor heat pump equipment.
  • Aux heat (auxiliary heat)Aux heat is a backup heat source that a heat pump thermostat turns on automatically when the heat pump needs help.
  • Btu (British thermal unit)A Btu is the heat needed to raise one pound of water by one degree Fahrenheit, and heat pump capacity is given in Btu per hour.
  • COP (coefficient of performance)COP is the heat a heat pump delivers divided by the electricity it uses, at one set of conditions.
  • DefrostDefrost is the cycle in which a heat pump briefly reverses to melt frost off its outdoor coil.
  • EER2EER2 is a cooling efficiency rating at a single hot test condition, in Btu per hour of cooling per watt.