The numbers
Since January 1, 2023, federal efficiency standards are rated with the updated SEER2, EER2 and HSPF2 test procedures. California falls in the Department of Energy's Southwest region, which adds an EER2 requirement for central air conditioners.
- Split-system ACs under 45,000 Btu/h: at least 14.3 SEER2, and EER2 of 11.7 (or 9.8 if the SEER2 is 15.2 or higher).
- Split-system ACs at 45,000 Btu/h or more: at least 13.8 SEER2, and EER2 of 11.2 (or 9.8 if the SEER2 is 15.2 or higher).
- Split-system heat pumps: at least 14.3 SEER2 and 7.5 HSPF2 (national standard).
SEER2 vs. EER2
SEER2 averages efficiency across a cooling season. EER2 measures efficiency at a single hot condition, which is closer to what an inland Southern California system faces on an August afternoon. Two systems with the same SEER2 can differ meaningfully on EER2.
For coastal Climate Zone 7 homes, SEER2 is usually the more useful comparison. For inland Climate Zone 10 homes in places like Escondido, El Cajon and Temecula, compare EER2 too.
How to check a quote
Ratings apply to a matched indoor and outdoor combination, not the outdoor unit alone. Ask for the AHRI certificate number for the exact pairing on the quote and look it up. If the installer swaps the indoor coil for a different model, the rating can change.
Questions
What is the minimum SEER2 for a new AC in California?
14.3 SEER2 for split-system ACs under 45,000 Btu/h and 13.8 SEER2 at 45,000 Btu/h and above, plus EER2 minimums.
Keep reading
Looking for city-specific rules? See our SoCal city guides.
Sources
Last checked October 2026.