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What changed in 2023
SEER (Seasonal Energy Efficiency Ratio) was the DOE's standard efficiency metric for residential air conditioners and heat pumps from 1992 through 2022. On January 1, 2023, DOE replaced it with SEER2 — same idea, stricter test conditions. Same day, the minimum federal efficiency standard also went up. Two changes, one date, a lot of confused quotes floating around ever since.
The physical equipment did not get worse. A 2019 unit rated 16 SEER still moves the same air, uses the same power, and produces the same cooling as it did the day it was built. What changed is how DOE measures it in the lab. And because the new test is harder, the number that comes out is smaller.
Why the number is lower for the same equipment
The main change is the external static pressure the equipment is tested against in the lab. Old SEER test: 0.1" WC (water column) — practically no resistance, like an air handler sitting on a bench with a fan blowing directly out the top. New SEER2 test: 0.5" WC — which is a much more realistic simulation of a real duct system with elbows, registers, and a filter in the way.
At higher external static pressure the blower has to work harder to move the same amount of air, which uses more electricity, which drops efficiency. Same physical equipment, more realistic test, lower number. Roughly 4.5–7% lower.
| Old SEER rating | Roughly equivalent SEER2 | What it means |
|---|---|---|
| 14 SEER | ~13.4 SEER2 | Below new minimum — no longer sold new. |
| 15 SEER | ~14.3 SEER2 | Below new minimum — no longer sold new. |
| 16 SEER | ~15.2 SEER2 | Right at the new southern minimum for split ACs. |
| 18 SEER | ~17.1 SEER2 | Mid-tier variable-speed territory. |
| 20 SEER | ~19.0 SEER2 | Premium variable-speed. |
| 22 SEER | ~20.9 SEER2 | Top-of-line inverter systems. |
The new federal minimums (Arkansas is Southern region)
DOE divides the country into three efficiency regions: North, Southeast, and Southwest. Arkansas is in the Southeast — the same region as Texas, Louisiana, Mississippi, Alabama, Georgia, and Florida. Southeast minimums are higher than Northern minimums because we run our AC more hours per year.
| Equipment class | Northern minimum | Southeast minimum (AR) |
|---|---|---|
| Split-system AC (under 45,000 BTU) | 14.0 SEER2 | 15.0 SEER2 |
| Split-system AC (over 45,000 BTU) | 13.8 SEER2 | 14.8 SEER2 |
| Heat pump (all sizes) | 15.2 SEER2 / 8.8 HSPF2 | 15.2 SEER2 / 8.8 HSPF2 |
| Packaged AC/heat pump | 14.4 SEER2 / 8.1 HSPF2 | 14.4 SEER2 / 8.1 HSPF2 |
What this actually means for you
Comparing 2020 quotes to 2026 quotes
Apply the ~5% adjustment before deciding which is "more efficient." A 16 SEER quote from 2020 and a 15 SEER2 quote from 2026 describe roughly the same physical efficiency.
Reading rebate applications
SWEPCO and the Federal 25C credit both specify SEER2 minimums now. Don't try to convert an old SEER number and submit it — the paperwork wants the number from the AHRI certificate under the new test.
Understanding "tier" language on quotes
Manufacturers renamed a lot of tiers. What used to be sold as "16 SEER" is now marketed as "15 SEER2 base efficiency," what used to be "18 SEER" is now "16.2 SEER2 enhanced." Same equipment lineup, new naming.
The staging conversation matters more
SEER2 is one number. The compressor and blower staging determines how the equipment actually behaves — see our companion article on <a href="/learning-center/equipment-brands/variable-speed-vs-single-stage">variable-speed vs. single-stage</a>.
The two myths this test change created
How to compare two quotes honestly
- 1
Step 1 — get both in SEER2 terms
If one quote lists SEER (from an older brochure) and another lists SEER2, multiply the SEER number by ~0.95 to get an apples-to-apples comparison.
- 2
Step 2 — check the AHRI certificate
The rated efficiency depends on the specific outdoor unit + indoor coil + air handler combination. Ask for the AHRI-matched combination reference (5-6 digit number). The efficiency on the AHRI certificate is the real number.
- 3
Step 3 — compare staging, not just efficiency
A 15.2 SEER2 variable-speed system will feel very different from a 15.2 SEER2 single-stage system in a Van Buren summer, even though the label number matches.
- 4
Step 4 — apply rebate math last
SWEPCO rebates and the Federal 25C credit kick in at specific SEER2 / HSPF2 thresholds. See our <a href="/learning-center/cost-guides/swepco-rebates-and-federal-25c-credit">rebates and 25C credit</a> guide for the current qualifying tiers.
Frequently asked
Is my old 16 SEER AC still "good"? +
Yes. The regulation applies to new installs. Your existing 16 SEER unit will continue to work at its rated efficiency until the day it fails — and it's roughly a 15 SEER2 equivalent in modern terms.
What's the difference between SEER2 and EER2? +
SEER2 is seasonal average efficiency across a range of conditions. EER2 is efficiency at a single hot-weather design condition (95°F outdoor). EER2 matters most for Arkansas summers because it tells you how efficiently the AC runs on the hottest, worst days — not just on average.
Do I need to upgrade to a SEER2-labeled unit to get the Federal 25C credit? +
Yes — the 25C credit requirements are written in SEER2 / HSPF2 terms. Any new install after Jan 1, 2023 is automatically SEER2-labeled, so this is only a concern for reused equipment. Full requirements in our rebates and 25C credit guide.
How much do I save going from 15 SEER2 to 18 SEER2 in Van Buren? +
Rough math: 5 months of cooling, average $110/month electric bill during cooling months, ~15% of which is AC. Bumping from 15 to 18 SEER2 saves roughly $60–$120/year on operating cost. Payback on the $2,000–$3,000 tier upgrade is 20+ years on efficiency alone — the reason to upgrade is comfort, not payback (see variable-speed vs. single-stage).
Where does the AHRI certificate come from? +
AHRI (Air Conditioning, Heating, and Refrigeration Institute) publishes matched-system efficiency ratings at ahridirectory.org. Any legitimate quote in Van Buren will include the AHRI reference number — that's the paper trail rebate and tax-credit paperwork ultimately checks.