SEER2 Explained: What Rating Do You Need?

A new central air conditioner installed in North Texas today must meet at least 14.3 SEER2 for units under 45,000 Btu/h or 13.8 SEER2 for larger systems, and most Collin County homes get the fastest payback somewhere in the 15 to 17 SEER2 range rather than at the top of the lineup. Trusted Heating & Air Conditioning, a TDLR-licensed Air Conditioning/Refrigeration Contractor (TACLA152199C, active through June 2027) based in McKinney, sizes SEER2 recommendations off actual North Texas run-time math instead of a flat sales script, whether the job is a straightforward tune-up or a full AC replacement. Texas sits in the U.S. Department of Energy’s Southeast region, so that SEER2 floor is the whole requirement, no add-on Energy Efficiency Ratio 2 (EER2) test applies here the way it does in Arizona, California, Nevada, and New Mexico. Paying up for a rating well past that floor feels like the cautious move, but SEER2 stops paying back at a certain point in this climate, and a bigger, higher-tier unit is usually the wrong answer if your home’s size and ductwork don’t call for it.

What does SEER2 actually measure

SEER2 (Seasonal Energy Efficiency Ratio 2) measures how much cooling a system delivers per watt-hour of electricity across a full season, tested under conditions closer to how ductwork actually restricts airflow in a real house. The Department of Energy updated the test procedure on January 1, 2023 (the M1 test), which pulled nominal ratings down roughly 4 to 5 percent compared to the old SEER number, without any equipment losing real-world capability. A system that would have carried a 15.0 SEER label before 2023 now carries a 14.3 SEER2 label. Same hardware, stricter test.

What’s the legal minimum SEER2 you can install in Texas today

As of 2026, Texas requires at least 14.3 SEER2 for split-system central air conditioners under 45,000 Btu/h (roughly 3.5 tons and smaller) and 13.8 SEER2 for units at or above that size. Contractors cannot legally install anything below those numbers on a new system. Nothing forces an existing, working system to be upgraded; the requirement only applies to new installs.

Does Texas require an EER2 rating too

No. An EER2 floor (11.7 for units under 45,000 Btu/h, 11.2 for larger units) applies only in the DOE Southwest region: Arizona, California, Nevada, and New Mexico. Texas falls under the Southeast region, where SEER2 is the only number that matters. If a contractor centers a Texas quote around hitting an EER2 target, ask them to point to the actual DOE Southeast region requirement; that’s usually a script written for a different climate.

How does SEER2 compare to the old SEER rating

Comparing a spec sheet from before 2023 to one from today gets confusing fast, since the numbers dropped without the equipment changing. As a rough rule, today’s SEER2 rating runs about 4 to 5 percent below the old SEER number for equivalent hardware.

Treat the right-hand column as approximate, useful for translating an old quote or a neighbor’s system, not as a substitute for the equipment’s actual rated SEER2.

Is paying for a higher SEER2 tier worth it in North Texas

Often, yes, up to a point. Collin County runs an air conditioner far more hours per year than most of the country, six-plus months of real cooling load with repeated stretches over 100°F, so the extra efficiency of a mid-tier system earns back its premium faster here than in a milder climate. Moving from the 14.3 SEER2 floor to a 16 to 17 SEER2 tier commonly adds a few hundred to around two thousand dollars to an installed quote, depending on the equipment line, tonnage, and whether the ductwork needs work to support it; a full breakdown of installed pricing factors lives in our AC replacement cost guide. Past that tier, the math flattens: pushing to 19 or 21 SEER2 usually costs more upfront than it saves in electricity over a typical 15 to 20 year North Texas system life, unless you’re planning to stay in the home well over a decade and run the system hard every summer. Chasing the highest number on the brochure is rarely the right answer for a homeowner who’ll move in five years.

Which SEER2 tier unlocks Oncor rebates

Oncor’s Take A Load Off, Texas program offers efficiency incentives for qualifying high-efficiency AC and heat pump upgrades, and heat pump incentives typically require a SEER2 rating around 16 or higher. Three things matter separately here: how the money arrives, what qualifies, and when it runs out. The money arrives as a discount an Oncor-approved Participating Service Provider applies directly to the installed price, not a check mailed to the homeowner. What qualifies is equipment above the SEER2 threshold, usually paired with a DOE-listed smart thermostat. When it runs out: funds are budgeted annually and awarded first-come, first-served, typically January or February through November. Amounts vary by system size and efficiency, from a few hundred to a couple thousand dollars; how the Oncor rebate mechanic actually works covers the paperwork end to end. If a rebate offer sounds like a fixed guaranteed dollar figure or a check in the mail, ask any contractor, including us, to show the incentive as a line item tied to their Participating Service Provider status.

Are older, lower-SEER2 systems grandfathered in

Yes. A system installed before the 2023 SEER2 rule, or one that simply carries a lower rating than today’s floor, is not in violation of anything and doesn’t need to be replaced. The 14.3/13.8 SEER2 minimum applies only when a system is newly installed.

How do you pick the right SEER2 tier for your home

Four factors decide it more than any brochure comparison. Run-time hours favor a higher tier: a home that runs its AC nearly nonstop from May through September recovers a tier upgrade faster than one that’s shaded, well-insulated, or lightly used. Years you plan to stay in the home matter directly: a 15-year time horizon lets a mid-tier system fully repay itself, while a five-year horizon usually doesn’t. Rebate eligibility can tip the decision, since landing in the ~16 SEER2 range for a heat pump opens Oncor incentive dollars that partly offset the premium. And staging matters as much as the SEER2 number itself; single-stage, two-stage, and variable-speed equipment deliver different comfort and efficiency even at the same rating, so the tier decision and the staging decision should happen together, not separately.

What should you check before you sign a SEER2 quote

• Quote at or above 14.3 SEER2 (under 45,000 Btu/h) or 13.8 SEER2 (45,000 Btu/h and up)? If not, it isn’t legal to install in Texas; ask for a compliant quote.
• Quote references an EER2 number for your Texas home? That’s a Southwest-region requirement, not one that applies here.
• Rebate mentioned? Confirm the tier actually meets the Oncor threshold and ask whether the contractor is an approved Participating Service Provider before counting on the discount.
• Planning to stay 10-plus years and run the system hard every summer? A step above the baseline tier usually pays back. Planning to move within five years? The baseline tier is usually the smarter spend.
• Rebate described as a fixed dollar figure or a check mailed to you? Get a second opinion; that isn’t how the program pays out.

A right-sized SEER2 recommendation depends on your home’s ductwork, insulation, and how long you’ll own it, not a single number from a blog post. Trusted Heating & Air Conditioning offers a free assessment and a written recommendation you can compare against any other quote; call (945) 333-4822, any hour, any day.

Ready to fix it right? get a free replacement assessment or call (945) 333-4822.