Key takeaways
- Since January 1, 2023, federal minimums are expressed in SEER2, EER2 and HSPF2, measured under an updated test procedure, so old SEER numbers and new SEER2 numbers are not directly comparable.
- Nationally, split-system central AC must meet 13.4 SEER2 and split-system heat pumps 14.3 SEER2 and 7.5 HSPF2[1].
- In the Southeast and Southwest, split AC below 45,000 Btu/h must meet 14.3 SEER2 and larger units 13.8 SEER2, based on where the unit is installed[1].
- Do not quote the federal 25C credit on new jobs: the IRS says it covers qualifying property placed in service before December 31, 2025[2].
What changed in 2023
Two things changed at the same time on January 1, 2023, which is why the topic still confuses customers and new staff. First, the Department of Energy updated the test procedure for central air conditioners and heat pumps. The new procedure uses higher external static pressure, closer to the duct conditions found in real homes, and its results are reported as SEER2 for seasonal cooling efficiency, EER2 for efficiency at a high outdoor temperature and HSPF2 for heating efficiency. Because the test is tougher, the same piece of equipment earns a lower SEER2 number than its old SEER number.
Second, the minimum efficiency standards themselves rose, and they were restated in the new metrics. The federal rules in 10 CFR 430.32 now set the minimums for products manufactured on or after January 1, 2023, with additional regional standards for air conditioners installed in the Southeast and Southwest[1]. When a customer says that a quote shows a lower rating than a quote from three years ago, the test change is often the reason, not worse equipment.
Never compare an old SEER rating with a new SEER2 rating as if they were the same scale. Compare SEER2 with SEER2, ideally from the AHRI certificate for the exact matched system.
The current federal minimums
The table summarizes the main residential product classes. Heat pumps carry one national standard. Air conditioners have a national minimum plus higher regional requirements in the Southeast and Southwest.
| Product class | National minimum | Southeast and Southwest |
|---|---|---|
| Split-system AC, under 45,000 Btu/h | 13.4 SEER2[1] | 14.3 SEER2[1] |
| Split-system AC, 45,000 Btu/h and up | 13.4 SEER2[1] | 13.8 SEER2[1] |
| Split-system heat pump | 14.3 SEER2 and 7.5 HSPF2[1] | Same national standard |
| Single-package AC | 13.4 SEER2[1] | Regional EER2 rules apply in the Southwest |
| Single-package heat pump | 13.4 SEER2 and 6.7 HSPF2[1] | Same national standard |
Source: Legal Information Institute, Cornell Law School, 2026[1]
Show the data
| Item | Value |
|---|---|
| Split AC, North | 13.4 SEER2 |
| Split AC under 45k Btu/h, Southeast and Southwest | 14.3 SEER2 |
| Split AC 45k Btu/h and up, Southeast and Southwest | 13.8 SEER2 |
| Split heat pump, all regions | 14.3 SEER2 |
The Southwest also sets EER2 minimums for air conditioners, which matter in hot, dry climates where peak-temperature efficiency drives demand on the grid. Check the EER2 value on the AHRI certificate, not only the SEER2, before quoting a condenser in Arizona, California, Nevada or New Mexico.
Which states are in which region
The regulation defines the regions by state[1]. Contractors near a regional boundary need to know them by heart, because the rule for split-system air conditioners follows the installation address, not the location of your shop or the distributor.
- Southeast: Alabama, Arkansas, Delaware, Florida, Georgia, Hawaii, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Virginia, the District of Columbia, Puerto Rico and the US territories.
- Southwest: Arizona, California, Nevada and New Mexico.
- North: every other state, where only the national minimums apply.
Heat pumps follow the national standard everywhere, which makes them simpler to stock across a regional line. Air conditioners that meet only the national 13.4 SEER2 minimum can be installed in northern states but not in Southeast or Southwest homes if the regional standard applies to that product class.
Why efficiency matters more in some markets
Air conditioning is nearly universal in the regions with the stricter standards. EIA found AC use highest in the South, at 93% of households, and the Midwest at 92%, with the West lowest at 73%[3]. Space heating and air conditioning together accounted for 52% of US household energy consumption in 2020[4]. In homes that run cooling for most of the year, the difference between a minimum system and a higher-efficiency system shows up on every summer bill, which gives your comfort advisors a concrete story to tell.
52%
of US household energy consumption went to space heating and air conditioning in 2020[4]
Ratings describe equipment tested in a lab. Installation decides what the customer actually gets. ENERGY STAR says improper installation can reduce HVAC system efficiency by up to 30%, and that sealing and insulating ducts can improve heating and cooling efficiency by as much as 20%[5]. A high-efficiency system on leaky ducts with the wrong charge can perform worse than a properly installed minimum-efficiency system.
Explaining ratings to customers
Start with what the number means
'SEER2 tells you how much cooling you get for the electricity used over a typical season. Higher means lower running costs for the same comfort.'
Explain the test change once
'Ratings changed in 2023 to a tougher test, so new numbers look lower than older ones. Compare new ratings with new ratings.'
Show the matched-system certificate
Give the AHRI reference number for the exact outdoor unit, indoor coil or air handler and furnace combination you are quoting.
Tie efficiency to their use
Ask how many months they run cooling and heating, and use that to decide whether a higher-efficiency tier makes sense.
Put installation on the table
Explain duct testing, sealing and proper charging as part of what they are paying for, because those decide real-world efficiency.
Selling above the minimum without overselling
Minimum standards set the floor, not the recommendation. Many customers will be well served by a minimum-efficiency system, and some will save real money with a higher tier. The goal of a good-better-best proposal is to make that trade-off visible, not to push everyone to the top option.
- Base the comparison on the customer's actual use: hours of cooling, heating fuel, how long they plan to stay in the home and their current bills.
- Show the running-cost difference as a range and explain the assumptions, rather than promising a specific saving.
- Point out non-efficiency benefits honestly, such as variable-speed comfort, humidity control and quieter operation, and do not dress them up as savings.
- Mention when a higher tier is unlikely to pay back, for example in a lightly used vacation home or a home the customer plans to sell soon.
- Keep claims tied to the AHRI rating of the exact system, and avoid quoting a manufacturer's best-case number for a different combination.
Customers who feel they were given an honest comparison come back for maintenance and refer neighbors. Customers who later discover that a promised saving was never realistic leave reviews about it, and those reviews outlast any single sale.
Tax credits and rebates in 2026
From 2023 the federal Energy Efficient Home Improvement Credit (25C) equaled 30% of qualified expenses, with a $2,000 annual cap for qualifying heat pumps[2]. The IRS says it applies to qualifying property placed in service from January 1, 2023 and before December 31, 2025, so it does not cover installs after that[2]. Remove it from sales sheets and website copy, and train comfort advisors not to mention it on new jobs. Utility and state rebates may still exist in your market; list the current ones on a single page that the office updates.
Example: a contractor on a regional boundary
Example (fictional): an HVAC company in Louisville, Kentucky also serves towns across the river in southern Indiana. Kentucky is in the Southeast region and Indiana is in the North. The company's warehouse holds 13.4 SEER2 split AC condensers for Indiana budget replacements and 14.3 SEER2 units for Kentucky. The dispatch software checks the job address and blocks a 13.4 SEER2 condenser from being assigned to a Kentucky install. The comfort advisors quote heat pumps more often near the boundary, partly because they follow one national standard and simplify stock.
Compliance checklist
- Quote from AHRI matched-system certificates, and attach the reference number to the proposal.
- Check the installation address against the regional list for every split AC sale.
- Record model and serial numbers of installed equipment, and keep invoices showing manufacture dates where it matters.
- Review EER2 as well as SEER2 for Southwest air conditioner jobs.
- Update price books, websites and brochures so they use SEER2 and remove expired tax credits.
- Train CSRs to answer the 'why is the number lower' question in one sentence.
Refrigerant rules changed at nearly the same time; see our guide to the A2L refrigerant transition and, for electrical work on new equipment, NEC code adoption by state.
Frequently asked questions
What is the minimum SEER2 rating in 2026?
Nationally, 13.4 SEER2 for split-system central air conditioners and 14.3 SEER2 for split heat pumps. In the Southeast and Southwest, split AC under 45,000 Btu/h must meet 14.3 SEER2, and larger units 13.8 SEER2.
Is SEER2 the same as SEER?
No. SEER2 uses an updated test with higher external static pressure, so the same equipment scores lower on SEER2 than on the old SEER scale. Compare SEER2 ratings only with other SEER2 ratings.
Do regional standards apply to heat pumps?
Heat pumps have a single national standard of 14.3 SEER2 and 7.5 HSPF2 for split systems. The regional standards apply to air conditioners.
Can homeowners still claim the federal 25C tax credit for a new heat pump?
The IRS says the credit applies to qualifying property placed in service before December 31, 2025, so installs after that do not qualify. Check for state and utility rebates instead.
References
Legal Information Institute, Cornell Law School (2026). 10 CFR 430.32: Energy and water conservation standards and their compliance dates (opens in a new tab) ↑
Internal Revenue Service (2025). Energy Efficient Home Improvement Credit (opens in a new tab) ↑
U.S. Energy Information Administration (2020). Nearly 90% of U.S. households used air conditioning in 2020 (opens in a new tab) ↑
U.S. Energy Information Administration (2020). Use of energy in homes (opens in a new tab) ↑
ENERGY STAR (U.S. EPA) (2026). Heat & Cool Efficiently (opens in a new tab) ↑