Last reviewed: August 2026 · By the HVAC Brief Editorial Team · Our sourcing and editorial standards
SEER2 is the federal efficiency rating that replaced SEER for equipment manufactured on or after January 1, 2023. The national minimum is 13.4 SEER2 for split system air conditioners and 14.3 SEER2 with 7.5 HSPF2 for split system heat pumps.
Air conditioners also carry a regional minimum that is higher than the national one. In the Southeast and Southwest, a split air conditioner under 45,000 Btu/hr must be at least 14.3 SEER2, and a unit rated below that cannot legally be installed there even though it can be sold elsewhere.
The rating change is not cosmetic. SEER2 is measured under a higher external static pressure than SEER was, which better reflects real ductwork, so the same physical equipment scores lower on SEER2 than it did on SEER. A unit that was 14 SEER is not 14 SEER2.
The national minimums
Under 10 CFR 430.32(c)(5), central air conditioners and central air conditioning heat pumps manufactured on or after January 1, 2023 must meet these floors. HSPF2 applies only to heat pumps.
| Product class | SEER2 minimum | HSPF2 minimum |
|---|---|---|
| Split system air conditioner, under 45,000 Btu/hr | 13.4 | n/a |
| Split system air conditioner, 45,000 Btu/hr and over | 13.4 | n/a |
| Split system heat pump | 14.3 | 7.5 |
| Single-package air conditioner | 13.4 | n/a |
| Single-package heat pump | 13.4 | 6.7 |
| Small-duct, high-velocity | 12.0 | 6.1 |
| Space-constrained air conditioner | 11.7 | n/a |
| Space-constrained heat pump | 11.9 | 6.3 |
The regional minimums that catch people out
Air conditioners carry a second, higher standard tied to where the unit is installed, not where it is sold. Under 10 CFR 430.32(c)(6), split system air conditioners installed on or after January 1, 2023 in the Southeast or Southwest must meet these levels.
| Product class | Southeast SEER2 | Southwest SEER2 | Southwest EER2 |
|---|---|---|---|
| Split air conditioner, under 45,000 Btu/hr | 14.3 | 14.3 | 11.7 or 9.8 |
| Split air conditioner, 45,000 Btu/hr and over | 13.8 | 13.8 | 11.2 or 9.8 |
Southeast covers Alabama, Arkansas, Delaware, Florida, Georgia, Hawaii, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, Oklahoma, Puerto Rico, South Carolina, Tennessee, Texas, Virginia, the District of Columbia and the US territories. Southwest covers Arizona, California, Nevada and New Mexico. The regulation states that any outdoor unit model with a certified combination rated below the applicable regional level cannot be installed in that region.
In the Southwest the EER2 requirement is conditional: 11.7 EER2 applies to units certified below 15.2 SEER2, and 9.8 EER2 applies at 15.2 SEER2 and above, with 11.2 and 9.8 for the larger capacity class.
Regional standards attach to installation, not sale. A distributor in a Northern state can legally stock a 13.4 SEER2 split air conditioner that cannot be installed in Texas or Arizona. Heat pumps do not carry the regional air conditioner standard, which is one reason the regional rules push some markets toward heat pumps.
What changed from SEER to SEER2
Before January 1, 2023, equipment manufactured from 2015 had to meet SEER 13 for split air conditioners and SEER 14 with HSPF 8.2 for split heat pumps. Those figures are not comparable with the SEER2 numbers above, because the test procedure changed.
| Period | Split AC minimum | Split heat pump minimum |
|---|---|---|
| Manufactured 2015 to 2022 | 13 SEER | 14 SEER, 8.2 HSPF |
| Manufactured 2023 onward | 13.4 SEER2 | 14.3 SEER2, 7.5 HSPF2 |
Because SEER2 testing uses higher external static pressure, converting between the two is approximate at best. Compare SEER2 with SEER2, and treat any single conversion factor you see quoted as a rule of thumb rather than a standard.
Frequently asked questions
What is the minimum SEER2 rating allowed?
Nationally, 13.4 SEER2 for split system air conditioners and 14.3 SEER2 with 7.5 HSPF2 for split system heat pumps, for equipment manufactured on or after January 1, 2023, under 10 CFR 430.32(c)(5). Air conditioners installed in the Southeast or Southwest face a higher regional minimum of 14.3 SEER2 under 45,000 Btu/hr.
What is the difference between SEER and SEER2?
SEER2 replaced SEER for equipment manufactured from January 1, 2023 and is measured under higher external static pressure, which better represents installed ductwork. The same physical unit scores lower on SEER2 than on SEER, so the two ratings are not directly comparable and no exact conversion exists.
Which states have higher SEER2 requirements?
The Southeast region (Alabama, Arkansas, Delaware, Florida, Georgia, Hawaii, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, Oklahoma, Puerto Rico, South Carolina, Tennessee, Texas, Virginia, the District of Columbia and the US territories) and the Southwest region (Arizona, California, Nevada and New Mexico) require split system air conditioners to meet 14.3 SEER2 under 45,000 Btu/hr and 13.8 SEER2 at or above that capacity. The Southwest adds an EER2 requirement.
Can I install a 13.4 SEER2 air conditioner in Texas?
No. Texas is in the Southeast region, where split system air conditioners under 45,000 Btu/hr installed on or after January 1, 2023 must be at least 14.3 SEER2. The regulation states an outdoor unit with a certified combination below the regional level cannot be installed there, even if it can be sold in other states.
Do heat pumps have regional efficiency standards?
The regional standards in 10 CFR 430.32(c)(6) apply to split system and single-package air conditioners, not heat pumps. Heat pumps meet the national minimum of 14.3 SEER2 and 7.5 HSPF2 for split systems nationwide.
Methodology
All figures are quoted from the current text of 10 CFR 430.32, Energy and water conservation standards and their compliance dates, paragraphs (c)(1) for the 2015 to 2022 standards, (c)(5) for the national SEER2 standards and (c)(6) for the regional standards, retrieved from the electronic CFR. We quote the regulation rather than paraphrasing it because the regional rules are the part most often reported incorrectly.
Limitations
- This covers federal minimums only. Utility rebate programmes and some state codes set higher thresholds.
- Minimums are floors, not recommendations. The efficient choice for a specific house depends on climate, ductwork and run hours.
- SEER and SEER2 are not interchangeable and we do not publish a conversion factor.
- Nothing here is engineering or legal advice. Confirm the current standard for your region before specifying equipment.
Sources
- US Department of Energy, 10 CFR 430.32, Energy and water conservation standards and their compliance dates, via eCFR.
The HVAC Brief is an independent trade publication. We do not sell equipment, take manufacturer advertising, or accept payment for placement in our research. Corrections welcome.
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