What Is SEER2?

SEER2 is the current efficiency rating for air conditioners and heat pumps, in effect since 2023. It replaced the old SEER rating with a tougher, more realistic test — and a higher SEER2 means lower cooling bills.

What does SEER2 actually measure?

SEER2 stands for Seasonal Energy Efficiency Ratio 2. It estimates how much cooling a system delivers over a whole season divided by the electricity it uses to do it. Think of it like miles per gallon for your AC: a higher number means more cooling for every dollar of electricity. Because we run our air conditioners so many months of the year in South Texas, that efficiency adds up fast.

How is SEER2 different from the old SEER?

SEER2 isn't a brand-new idea — it's the same concept measured with a harder test. Starting in 2023, the U.S. Department of Energy updated how systems are tested so the lab conditions better reflect real-world ductwork and airflow. Because the new test is tougher, the same equipment will usually show a slightly lower SEER2 number than its old SEER number. The unit didn't get worse — the measuring stick got more honest. So when you compare quotes, make sure you're comparing SEER2 to SEER2, not mixing the two.

What about EER2 and HSPF2?

You'll see two related ratings on the same equipment:

• EER2 measures efficiency at a single hot, peak-demand condition — useful for a place like the Valley where 100-degree afternoons are normal.
• HSPF2 rates heating-season efficiency for heat pumps. It only matters if your system also heats — which most modern systems here do. See AC vs. heat pump for how that choice works.

What SEER2 should I look for in South Texas?

There's a federal minimum SEER2 you can't buy below, and the southern region — including Texas — has a higher minimum than the colder northern states, precisely because we cool so much. Beyond that minimum, the right number is a balance: a higher SEER2 costs more up front but trims your monthly bills, and the payback is strongest in a climate like ours where the system runs hard. There's also a point of diminishing returns, so the best value usually isn't the cheapest or the most expensive unit.

Does a higher SEER2 actually pay off?

Often, yes — but only if the system is sized and installed correctly, because a poor install erases the efficiency you paid for. Real-world savings also depend on your home, your ductwork, and how you use it. When you're weighing efficiency against budget, our AC replacement cost guide lays out the trade-offs, and you can spread a higher-efficiency system over monthly payments so the upfront cost isn't a barrier. Curious which brand does efficiency well? Read is Daikin a good brand?