SEER2 is the efficiency rating on every central air conditioner sold in the United States since 1 January 2023. It replaced SEER. The number looks similar, the test behind it is harder, and in Texas it also sets a legal floor on what a contractor may install.
What the rating measures
SEER stands for Seasonal Energy Efficiency Ratio. It is cooling output over a season divided by the electricity used to produce it. A higher number means more cooling for the same power.
SEER2 measures the same thing with a more realistic test. The old procedure ran the equipment against almost no duct resistance. The new one, Appendix M1, tests typical ducted equipment against a much higher external static pressure, which is far closer to a real house with real ductwork.
Because the test is harder, the same physical unit scores lower under SEER2 than it did under SEER. For a ducted split system the drop is around 5 percent: a 15 SEER condenser is rated 14.3 SEER2. That is not a downgrade. It is a different ruler.
Two related ratings changed at the same time:
- EER2 replaced EER, which is efficiency at one fixed hot condition rather than across a season.
- HSPF2 replaced HSPF, which is the heating rating for heat pumps.
The Texas minimum
Efficiency standards for central air conditioners are regional. The Department of Energy divides the country into North, Southeast and Southwest, and Texas is in the Southeast region.
Two things follow from that, and both matter when you buy.
- 01The Southeast standard is enforced at the date of installation, not the date of manufacture. In the North the rule follows when the unit was built, so old stock can legally be installed. Here it cannot.
- 02For split-system air conditioners in the Southeast, the minimum is 14.3 SEER2 below 45,000 BTU per hour and 13.8 SEER2 at 45,000 and above.
So if somebody offers you a cheap new split system in New Braunfels below that floor, the installation itself is the problem, not just the efficiency. DOE can require the installer to replace a non-compliant unit at no cost to the homeowner.
Is a higher SEER2 worth the money?
Sometimes. Three things decide it.
- 01Run hours. Our cooling season is long, so efficiency earns back faster here than it would in a mild climate. That argues for paying up.
- 02Ductwork. A high-efficiency system on leaky or undersized ducts cannot deliver its rating. The rating is earned in a laboratory with proper airflow. Fix the ducts, or the difference goes into the attic.
- 03Sizing. An oversized system short cycles, removes less humidity, and feels worse at any rating. A load calculation decides the size, not a rule of thumb and not the size of the old unit.
There is also a comfort argument the number does not show. Two-stage and variable-speed equipment runs longer at lower output, which holds temperature more evenly and pulls more moisture out of the air. In a humid Texas summer that is often what people actually notice.
What we do about it
When we quote AC installation we look at the house, not only the old nameplate. Size, duct capacity, line set, drainage and electrical all decide whether a system performs the way its label says.
If the system you have is still serviceable, we will say so. AC maintenance on a working unit is far cheaper than replacing one that had years left in it.
Talk it through
Vetter Air is family owned, licensed by the Texas Department of Licensing and Regulation as TACLA022794C, and has served New Braunfels for more than 20 years.
Call (830) 624-7079 or ask us for a quote. We serve New Braunfels, San Antonio, San Marcos, and the towns in between.