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Key takeaways
- SEER2 compares the cooling a system delivers over a season with the electricity it uses. Higher is more efficient.
- Since 2023, new split-system central ACs installed in the Southeast, including Louisiana, must reach at least 14.3 SEER2, or 13.8 SEER2 for larger systems.
- SEER2 numbers look lower than old SEER numbers for the same equipment because the test is tougher, not because the equipment got worse.
- Real savings depend on how much you cool, your electric rate and how well the system is installed.
What SEER2 measures
SEER stands for Seasonal Energy Efficiency Ratio. It compares the cooling a system delivers over a typical season with the electricity it uses. In 2023 the Department of Energy updated the test to better reflect real duct systems, and the new number is called SEER2. A higher SEER2 means more cooling for each dollar of electricity.
The minimum for new systems in Louisiana
1992
10 SEER, the first national minimum.
2006
13 SEER.
2015
14 SEER in the Southeast, including Louisiana.
2023
14.3 SEER2, equal to 15 SEER, for systems under 45,000 Btu/h; 13.8 SEER2 for larger ones.
If your system was installed before 2006, it may be rated 10 SEER or less. On paper, a new system at today’s minimum uses about a third less electricity for the same cooling, and higher-efficiency systems save more.
Estimate your savings
Interactive tool
Cooling cost estimator
Compare your current system with a newer one, using your own numbers.
Not sure? Compare a summer power bill with a spring bill, when you barely run the AC, and multiply the difference by your number of hot months.
Estimated savings
$225/yr
About $2,250 over 10 years
How we estimate: your cooling cost × (current SEER2 ÷ new SEER2). Older ratings are converted to SEER2. Older systems often perform below their original rating, so real savings can be higher or lower.
An estimate for comparing options, not a guarantee. Installation quality, ductwork, thermostat habits and weather all affect the result.
Efficiency is more than the number
- Installation quality: the right refrigerant charge and airflow are needed to reach the rated efficiency.
- Matched parts: the rating applies to a specific indoor and outdoor combination.
- Ductwork: leaky ducts in a hot attic can waste much of the gain.
- Variable-speed equipment: runs longer at lower speeds, which can also help with humidity in our climate.
- Thermostat habits: the Department of Energy says you can save as much as 10% a year by adjusting the thermostat 7 to 10 degrees for 8 hours a day, such as while you’re at work. In humid weather, a smaller adjustment helps keep moisture in check.
Common questions
Sources
We checked the facts in this guide against these public sources.
- U.S. Department of Energy — 2023 central air conditioner and heat pump standards FAQ (PDF)
- U.S. Department of Energy — Programmable thermostats
- ENERGY STAR — When is it time to replace?
This guide is general information for homeowners, not a diagnosis of your system. If you smell gas or a carbon monoxide alarm sounds, leave the house and call 911 or your gas utility first.