SEER2 efficiency rules for replacing an AC in Louisiana

By Gail Barlow, HVAC Guides Editor · Updated September 2026

What SEER2 is

SEER2 is the seasonal efficiency rating used for central air conditioners and heat pumps from 2023 onward. It replaced the older SEER rating and uses a test that better reflects real ductwork, with more resistance to airflow than the old test assumed.

Because the test is tougher, the numbers are lower than the old SEER numbers for the same equipment. A 14.3 SEER2 system is roughly equivalent to a 15 SEER system under the old method, so the two ratings cannot be compared directly.

The minimums that apply in Louisiana

Louisiana is in the Southeast region of the federal efficiency standards. In this region, split-system air conditioners below 45,000 BTU per hour must be at least 14.3 SEER2, and split systems at or above 45,000 BTU must be at least 13.8 SEER2. Split-system heat pumps must be at least 14.3 SEER2 and 7.5 HSPF2 everywhere in the country, and single-package units at least 13.4 SEER2.

In the Southeast, the air conditioner rules are enforced by the date of installation. A split AC that does not meet the 2023 minimum cannot be installed, even if it was built earlier.

Why the match between parts matters

A split system's rating applies to a specific combination of outdoor unit and indoor coil or air handler. Pairing a new outdoor unit with an old coil, or with a coil that is not a rated match, can mean the system does not meet the rating on the label, and it may not meet the minimum at all.

When you replace a system, ask for the matched combination and its certified rating. Reputable installers can show you the rating for the exact pair being installed.

Is a higher rating worth it here?

In a long cooling season, efficiency pays back faster than in milder places, because the system runs so many hours. But the biggest comfort gains here often come from variable-speed or two-stage equipment, which runs longer at lower speeds and pulls more moisture out of the air.

A modest step above the minimum, installed well, often beats a top-rated unit installed poorly. Duct sealing, correct sizing and a proper refrigerant charge affect real efficiency as much as the number on the label.

What to ask about refrigerant

Manufacturers stopped building new residential split systems that use R-410A at the start of 2025, and new equipment now uses lower-impact refrigerants such as R-454B or R-32. Federal rules on installing leftover R-410A equipment have changed more than once, so if a quote uses R-410A, ask why and how future service will be handled.

For most homeowners the simple question is: which refrigerant does this system use, and is it a current product line? That avoids buying the last of an outgoing design without knowing it.

Heat pumps and the rules

Heat pumps carry both a cooling rating (SEER2) and a heating rating (HSPF2). In a mild winter like ours, a heat pump that meets or exceeds the minimums is often the most efficient way to heat and cool, especially when it replaces electric strip heat or an aging furnace.

If you are replacing a furnace and AC together, compare a heat pump option on the same quote.

Reading a replacement quote

A clear quote names the outdoor unit and indoor coil or air handler by model, states the matched SEER2 rating, the refrigerant and the warranty terms, and says what is included: line set, pad or stand, drain work, electrical and any duct repairs. If a quote only lists tonnage and a brand, ask for the details before deciding.