What Is SEER2? The 2023 Minimums by Region, Explained

By Ray Bennett · Updated 2 October 2026 · 5 min read · Checked against the sources at the end

What Is SEER2? The 2023 Minimums by Region, Explained

Short answer

SEER2 is the seasonal efficiency rating DOE has required on central air conditioners and heat pumps since 1 January 2023, from a new test meant to reflect real installations. It is not directly comparable with the old SEER. The minimum for a split system AC is 13.4 SEER2 in the North and 14.3 in the Southeast and Southwest, and a split heat pump needs 14.3 SEER2 and 7.5 HSPF2 anywhere.

SEER2 is the efficiency rating on every central air conditioner and heat pump made since 1 January 2023. The Department of Energy says the higher the number, the less electricity the system uses to cool your home, and that the new test behind it is meant to better reflect real world installation and use.

This page sets out DOE’s minimums by region, the ratings that sit beside SEER2, and what the rules mean when you replace a system.

Before you start

What to carry: a torch and a pen, to copy the model numbers off the outdoor unit and the indoor coil. Ten minutes.

Gas or electric? Either. SEER2 rates the cooling, whether the heat comes from a gas furnace or a heat pump. A heat pump also has an HSPF2 rating for its heating. A gas furnace is rated by AFUE instead.

Know your region. DOE splits the country by heating degree days. States with 5,000 or more are the North, and the rest are the South, split again into a hot dry Southwest and a hot humid Southeast.

What DOE is firm about. Not comparable with the old SEER. DOE says SEER2, HSPF2 and EER2 are similar to the old ratings but not directly comparable. Compare a new system’s SEER2 only with other SEER2 figures.

The law in the South. DOE says it is illegal for a contractor to install a split system air conditioner that does not meet the regional standard in the Southeast or Southwest.

No exemptions. DOE says there are no delays or special exemptions from the 1 January 2023 date.

The minimums by region

DOE's 2023 minimums for a split system under 45,000 BTU an hour, just under four tons, and the ENERGY STAR level above them.

Check 1

Find the minimum where you live

North. A split system air conditioner needs at least 13.4 SEER2.

Southeast. 14.3 SEER2 for systems under 45,000 BTU an hour, and 13.8 for larger ones. DOE lists Alabama, Arkansas, Delaware, Florida, Georgia, Hawaii, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Virginia, the District of Columbia and the U.S. territories.

Southwest. Arizona, California, Nevada and New Mexico. The same SEER2 as the Southeast, plus, under 45,000 BTU an hour, an EER2 of 11.7, or 9.8 for systems rated 15.2 SEER2 or more.

Heat pumps. The standard is national: a split system heat pump needs 14.3 SEER2 and 7.5 HSPF2, and a single package heat pump 13.4 SEER2 and 6.7 HSPF2.

The other ratings

Check 2

Read EER2 and HSPF2 as well

SEER2. DOE describes SEER as the total heat removed over a cooling season divided by the electricity used over that season. SEER2 is the same idea from the new test.

EER2. DOE says EER measures efficiency at peak load, when the system is working hardest at 95°F, which matters most in hot dry climates. That is why the Southwest has an EER2 minimum.

HSPF2. DOE says the higher the heating seasonal performance factor, the less electricity a heat pump uses to heat your home.

ENERGY STAR. Its current mark asks for at least 15.2 SEER2 on a split system, with 12.0 EER2 on an air conditioner and 11.0 EER2 and 7.8 HSPF2 on a heat pump.

What the rules mean when you replace

Which date DOE's rules follow in each region, and the one that catches out a half replacement.

Check 3Part of a good quote

Check the dates and the match

In the North. DOE says the rules follow the date of manufacture. A unit made before 1 January 2023 that met the old standard may still be installed, and one made after must meet the new one.

In the South. The rules follow the date of installation. From 1 January 2023 a split system air conditioner installed in the Southeast or Southwest must meet the regional standard, whenever it was made.

A new outdoor unit on an old coil. DOE says a replacement outdoor unit installed with an existing indoor unit is compliant only if the maker certified that outdoor unit on its own, with no match, under the new test.

Combinations. DOE says a system of parts that was never certified as a combination is not compliant. Ask for the rating of the exact outdoor unit and coil being quoted.

Is a higher rating worth it?

Check 4Free to ask

Weigh the rating against the price

What DOE says. DOE says a unit with a higher SEER rating could cost more but will save money on the electricity bill, and that the new standards lower utility bills.

One example. DOE gives typical savings from the regional standard in the hottest, driest climate as $150 on average over the life of the air conditioner.

The size matters too. A high rating does little for a system that is the wrong size for the house: what size AC unit you need.

The refrigerant changed too. New systems built since 2025 use a lower impact refrigerant: the R-22 and R-410A phase out.

Questions people ask

What is the difference between SEER and SEER2?

SEER2 comes from DOE’s newer test, meant to better reflect real installations. DOE says the two are similar but not directly comparable, so compare SEER2 only with SEER2.

What is the minimum SEER2 in my state?

For a split system air conditioner, 13.4 in the North and 14.3 in the Southeast and Southwest for systems under 45,000 BTU an hour. Split system heat pumps need 14.3 anywhere.

Can I still get a 13.4 SEER2 air conditioner in Texas or Florida?

Not installed as a new split system. Both are in DOE’s Southeast region, where the minimum is 14.3 SEER2 for systems under 45,000 BTU an hour.

Can I replace just my outdoor unit?

DOE says a new outdoor unit with an existing indoor coil is compliant only if the maker certified that outdoor unit on its own under the new test. Ask the installer to show it.

What does HSPF2 mean?

The heating seasonal performance factor from the new test. DOE says the higher it is, the less electricity a heat pump uses to heat your home.

What SEER2 does ENERGY STAR require?

At least 15.2 SEER2 for a split system, with 12.0 EER2 for an air conditioner, and 11.0 EER2 and 7.8 HSPF2 for a heat pump.

Sources: U.S. Department of Energy "2023 Energy Conservation Standards for Central Air Conditioners and Heat Pumps: Frequently Asked Questions" (final guidance, 5 October 2022), and the ENERGY STAR Version 6.2 Central Air Conditioner and Heat Pump specification