Reading SEER2, HSPF2, and EER2 on a quote

The person in the driveway is talking about SEER2 like you already know it. You probably remember SEER from the last air conditioner, and the new sticker is a smaller number, which feels like a downgrade. It usually is not. The test got harder in 2023, so the same class of machine prints a lower score.

A heat pump has three of these: SEER2 for the cooling season, HSPF2 for the heating season, and EER2 for a single hot afternoon. An air conditioner has the two cooling numbers and no HSPF2, because it does not heat. None of them is the size of the machine, and none of them is your bill. They are lab ratios. The quote still has to fit this house.

What do the three stickers mean?

SEER2 (Seasonal Energy Efficiency Ratio 2) is total cooling delivered over a made-up cooling season, in Btu, divided by the electricity used, in watt-hours. Higher means the lab season used less power per unit of cooling. ENERGY STAR’s definition is the same idea: heat removed from the house divided by watt-hours in.

HSPF2 (Heating Seasonal Performance Factor 2) is the heating version of that, for heat pumps only. DOE scores it against a heating season in climate Region IV, which is a mixed-cold test climate, not your January. A great HSPF2 can still hide a weak night at 5°F. The cold-climate heat pump page is that winter table.

EER2 (Energy Efficiency Ratio 2) is cooling at one nasty outdoor condition, not a season. Think of it as the 95°F afternoon number. If you live where the unit sits at that load for weeks, EER2 is the sticker that tracks the peak bill better than SEER2. DOE only requires an EER2 minimum for some air conditioners in the Southwest. Heat pumps still publish it.

ENERGY STAR: heat pump key product criteria

Why did my 16 SEER turn into 15 SEER2?

The old SEER, EER, and HSPF tests (Appendix M) used a duct system that was too easy on the indoor fan. Appendix M1, which is the 2023 test, raises the external static pressure the fan has to push against, to about 0.5 inches of water on typical ducted units, instead of the old 0.1 to 0.2. NYSERDA’s one-pager on Appendix M1 also notes a harder heating load line, more realistic coil-only fan power, and a 5°F heating test point that the old HSPF math did not really use.

NYSERDA: air-source heat pump efficiency ratings, Appendix M1 (PDF)

The machine did not get worse. The homework got closer to a house with actual ducts. RESNET publishes conversion factors so older energy models can swallow the new labels: for a ducted split, SEER2 is about 0.95 times old SEER, and HSPF2 is about 0.85 times old HSPF. Ductless systems sit closer to 1.00 on cooling. Those are category factors, not a promise for the outdoor unit in your driveway. If a bid still says “16 SEER” in 2026, ask for the AHRI SEER2 of the matched pair.

RESNET: SEER2 and HSPF2 conversion factors (PDF)

A rough translation people use: 14 SEER is in the neighborhood of 13.4 SEER2, 15 SEER around 14.3 SEER2, 16 SEER around 15.2 SEER2, and 8.8 HSPF around 7.5 HSPF2. Use that to read an old brochure. Do not convert a quote by hand and call it certified.

What is the legal minimum where I live?

DOE’s floor is in 10 CFR 430.32. For equipment manufactured on or after January 1, 2023:

Split-system heat pumps, nationwide: 14.3 SEER2 and 7.5 HSPF2.

Split-system air conditioners, nationwide manufacture: 13.4 SEER2. If the unit is installed in the Southeast or Southwest, the floor goes up: 14.3 SEER2 if cooling capacity is under 45,000 Btu/h, 13.8 SEER2 at 45,000 Btu/h and above.

Single-package heat pumps: 13.4 SEER2 and 6.7 HSPF2. Single-package air conditioners: 13.4 SEER2.

Southwest air conditioners also have an EER2 floor. For a split AC under 45,000 Btu/h, that is 11.7 EER2 if the certified SEER2 is under 15.2, and 9.8 EER2 if SEER2 is 15.2 or higher. Bigger splits use 11.2 / 9.8. Packaged AC in the Southwest needs 10.6 EER2.

eCFR: 10 CFR 430.32

DOE: 2023 central AC and heat pump standards FAQ (PDF)

Southeast, in that FAQ, is Alabama, Arkansas, Delaware, Florida, Georgia, Hawaii, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, Oklahoma, Puerto Rico, South Carolina, Tennessee, Texas, Virginia, D.C., and the territories. Southwest is Arizona, California, Nevada, and New Mexico. Everyone else is North for the AC regional rule. Heat pumps do not pick up those extra SEER2 floors. A 14.3 / 7.5 heat pump is legal in Minneapolis and in Miami.

A leftover 14 SEER air conditioner built before 2023 is a different conversation (inventory and install rules). A 2026 bid should already be speaking SEER2.

When does ENERGY STAR actually mean something?

Federal minimum is the floor you can sell. ENERGY STAR is a higher bar, and rebate forms often want that bar, not “pretty good.”

On ENERGY STAR’s current heat-pump criteria, a split system wants at least 15.2 SEER2, 7.8 HSPF2, and 11.0 EER2. Packaged equipment wants 15.2 SEER2, 7.2 HSPF2, and 10.0 EER2. Cold Climate is a separate stamp: 8.1 HSPF2 ducted or 8.5 non-ducted, still 15.2 SEER2, plus the 5°F tests (COP at least 1.75, and at least 70% of 47°F heating capacity).

If the quote says ENERGY STAR and the AHRI certificate is 14.3 / 7.5, it is the legal minimum with a logo problem. Look up the outdoor and indoor model numbers together in the AHRI directory. Mix-and-match coils can print a pretty outdoor sticker and a worse system rating.

Which number should I actually shop?

Hot-dry (Phoenix, Las Vegas, inland California). EER2 first on an air conditioner, because the unit lives near the 95°F test. SEER2 still has to clear the Southwest floor. A high SEER2 with a soft EER2 is a machine that looks efficient in the shoulder seasons and works harder at 5 p.m. in July.

Hot-humid (Houston, Atlanta, Tampa). SEER2 and latent (humidity) control. A single-stage 14.3 SEER2 that short-cycles will feel clammy even if the sticker is legal. Variable-speed is how people buy dehumidification, not how they buy a number.

Cold (Minneapolis, Buffalo, Denver winters). HSPF2 is the seasonal heating sticker. Capacity at your design temperature is the thing that keeps the strips off. Do not pay a SEER2 premium to solve a January problem. The cold-climate page is the markup list for that bid.

Mixed (Ohio, Maryland, the Carolinas). You will run both seasons. ENERGY STAR’s 15.2 / 7.8 split-system line is a reasonable “better than the floor” without pretending 20 SEER2 is free. If last winter’s gas bill is the reason you are shopping, read HSPF2 and the backup-heat cutoff before you argue about cooling.

Ducts steal whatever you paid for. A 18 SEER2 outdoor unit on leaky attic flex is a 14 SEER2 house. The weatherize order of work still applies: seal, then argue about stickers.

Does a higher SEER2 pay for itself?

EnergySage’s 2026 marketplace average for a heat pump install is about $15,393 before incentives, with ducted around $14,529 and whole-home mini-splits around $25,957. Those are mixed quotes, not a SEER2 price list. The jump from a legal-minimum 14.3 to a 15.2 ENERGY STAR unit is often a different indoor coil, a different compressor, and a different bid, not a $400 add-on.

EnergySage: heat pump cost

A higher SEER2 uses less electricity per unit of cooling in the lab season. Your bill still depends on hours, your rate, how leaky the house is, and whether the installer sized the machine to a written load (Manual J). The operating cost page is the rate math. This page is whether the sticker on the quote is even the right sticker.

The federal 25C credit that used to care about ENERGY STAR heat pumps is done for equipment placed in service after December 31, 2025. Do not let a 2026 bid subtract $2,000 of IRS money because the leave-behind still has 2025 language. State and utility rebates may still want SEER2 / HSPF2 floors. Those are local, and they want model numbers.

IRS: Energy Efficient Home Improvement Credit

What should two bids look like next to each other?

Same house, mixed climate, existing ducts, replacing a dead AC and an aging furnace with a ducted heat pump.

Bid A prints 14.3 SEER2 and 7.5 HSPF2, the national heat-pump floor. Indoor coil is “we have one in the truck.” No AHRI certificate number. Heating capacity shown only at 47°F. Price sits near the EnergySage ducted average, or well under it.

Bid B prints 15.2 SEER2, 8.1 HSPF2, and an EER2, with an AHRI reference for that outdoor unit and that air handler. Heating capacity at 17°F and 5°F is in the packet. Backup strips or dual-fuel cutoff is written. Price is higher.

Bid A can be legal. It is also how you buy strips that run all January, or a coil that was never in the rating. Bid B can still be oversized. The quote checklist is the rest of the markup. If Bid B is thousands more only because the SEER2 is 18, and the ducts are still the original 1994 flex, you are buying a sticker for a leak.

Mini-splits often show very high SEER2 because the indoor head is in the room. Compare them to other mini-splits, not to a ducted 15.2, unless you are also comparing the job: one miserable room versus the whole house. That split lives on the mini-split page.

What goes wrong after you sign?

The brochure is 16 SEER. The AHRI sheet for the pair you actually installed is 14.3 SEER2. The rebate form bounces.

Someone sold “18 SEER2” on an outdoor unit that was rated that high with a different indoor coil.

EER2 is missing on a Phoenix air-conditioner bid, and July afternoons are the whole point.

HSPF2 is the hero number on a Minnesota bid, and there is still no 5°F capacity row.

The installer sized by square footage, then used a high SEER2 to argue the house would be cheap to run. Stickers do not fix a load they never calculated.

How do I read this week’s quotes?

1. Write down whether you are buying an air conditioner, a heat pump, or both, because HSPF2 only exists on the heat pump.
2. Circle SEER2, HSPF2, and EER2 on each bid, and throw out leftover SEER-only language until they reprint it.
3. Check the legal floor for your region and product: 14.3 / 7.5 for a split heat pump everywhere, higher SEER2 (and maybe EER2) for an air conditioner in the Southeast or Southwest.
4. Look up the outdoor and indoor model numbers as a pair in the AHRI directory, not as two pretty stickers.
5. Pick the sticker that matches the season that hurts: EER2 in a hot-dry peak, HSPF2 plus 5°F capacity in a real winter, SEER2 when you run the cooling season hard.
6. Ask what the extra money is buying if one bid is 18 SEER2 and the other is 15.2: a matched coil, variable speed, or just a number.

You can compare two machines with these ratings. You cannot tell from SEER2 alone whether the quote is the right size for your house.