Guide
SEER2 and EER2 in California: the Southwest region rules
Updated
Efficiency ratings are the part of an HVAC quote most often used to justify an upsell. Here is the legal floor, its source, and where paying more buys something.
SEER2 replaced SEER, and the test got harder
From January 1, 2023, the Department of Energy moved to SEER2, EER2 and HSPF2. These are measured under a test procedure with higher external static pressure, meant to reflect real installed duct systems rather than laboratory conditions.
A SEER2 number is not directly comparable to an older SEER number on the same equipment. So do not let anyone tell you your "14 SEER" system beats today's minimum without checking which metric they mean.
The national manufacturing minimum
10 CFR 430.32(c)(5) covers equipment manufactured on or after January 1, 2023. It sets minimum 13.4 SEER2 for split-system air conditioners and 14.3 SEER2 with 7.5 HSPF2 for split-system heat pumps (eCFR). Heat pumps have a single national minimum. Air conditioners then have a second, regional layer.
California is in the Southwest region, and it is stricter
DOE defines three regions for central air conditioner standards. The Southwest is Arizona, California, Nevada and New Mexico; the Southeast is a long list of hot-humid states; the North is everything else (energy.gov). For split-system air conditioners installed in the Southwest on or after January 1, 2023, 10 CFR 430.32(c)(6) requires:
| Certified cooling capacity | SEER2 | EER2 |
|---|---|---|
| Under 45,000 Btu/h | 14.3 | 11.7 if certified SEER2 is under 15.2; 9.8 if SEER2 is 15.2 or above |
| 45,000 Btu/h and above | 13.8 | 11.2 if certified SEER2 is under 15.2; 9.8 if SEER2 is 15.2 or above |
The EER2 requirement is the Southwest's distinguishing feature, and it exists for a reason. EER2 is measured at a 95 degree F outdoor rating condition, so it shows how the unit behaves on a genuinely hot afternoon, not across an averaged season. In a hot-dry climate, that is the number that matters to your July electricity bill.
This is an installation rule, not just a manufacturing rule
The regulation is explicit. "Any model of outdoor unit that has a certified combination with a rating below the applicable standard level(s) for a region cannot be installed in that region". DOE enforces this against installers. Its enforcement page describes:
- requesting records from installers
- issuing a Notice of Violation
- offering an incentive to "remediate" a violation by replacing the noncompliant air conditioner "at no cost to the consumer"
- routine violators being cut off by distributors and manufacturers (energy.gov)
If someone offers you a cheap out-of-region unit, the exposure is theirs and the fix is at their cost, but the disruption is yours.
Where paying for more efficiency is worth it
- Long cooling season, high rates. Inland California runs the compressor for months, and higher electricity prices shorten the payback on a better unit.
- Variable-speed equipment buys comfort and quieter operation as well as efficiency, and those are the benefits people actually notice.
- Leaky ducts cancel the upgrade. Paying two efficiency tiers up while leaving ducts unsealed in a hot attic is money spent in the wrong place. Fix the distribution first.
- Ask for the payback math in writing, using your own electricity rate. If a contractor cannot produce it, the upgrade is a sales preference, not an engineering one.