What the ratings mean
- SEER2: seasonal cooling efficiency, tested under conditions closer to real ductwork than the old SEER. A SEER2 number is lower than the old SEER for the same unit.
- EER2: cooling efficiency at a single hot test condition, important in the desert Southwest.
- HSPF2: seasonal heating efficiency for heat pumps.
- AFUE: the share of fuel energy a furnace turns into heat.
Federal minimums (since January 1, 2023)
| Region | Split central AC | Split heat pump |
|---|---|---|
| North | 13.4 SEER2 | 14.3 SEER2 / 7.5 HSPF2 |
| Southeast | 14.3 SEER2 (under 45,000 Btu/h); 13.8 SEER2 (larger) | 14.3 SEER2 / 7.5 HSPF2 |
| Southwest | As Southeast, plus EER2 minimums | 14.3 SEER2 / 7.5 HSPF2 |
ENERGY STAR
ENERGY STAR certified split central ACs and heat pumps currently need at least 15.2 SEER2, with additional EER2 and (for heat pumps) HSPF2 requirements. You can look up the certified rating of your exact combination in the AHRI directory.
Is higher efficiency worth it?
It depends on how many hours you run the system and your energy prices. In hot climates with long cooling seasons, higher SEER2 pays back faster. Variable-speed systems also improve humidity control and comfort, which some homeowners value as much as savings.
