AC Replacement Austin

SEER2 ratings, refrigerants, and the rules for a new AC in Texas

A new system’s efficiency rating has to meet the federal minimums that apply in Texas. You’ll also need to account for the refrigerant change, sizing rules, and permits required by Austin-area cities.

Updated October 2026

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What SEER2 measures

SEER2 rates how efficiently a cooling system uses electricity over a whole season. A higher number means less electricity used per unit of cooling. It replaced SEER on January 1, 2023, when the U.S. Department of Energy adopted a new test procedure called M1.

AHRI says the M1 test raises external static pressure, the resistance air meets as it moves through ductwork, by up to five times to better match real ductwork. That makes M1 ratings read lower, while minimally compliant products under the new test are about 7% more efficient. EER2 measures efficiency when the system works hardest, and the U.S. Department of Energy calls EER a measure of peak-load efficiency. HSPF2 measures a heat pump’s heating efficiency.

Minimum ratings in Texas

The federal minimums in the table come from the U.S. Department of Energy’s 10 CFR 430.32 and took effect January 1, 2023. Texas is in the Southeast region, so the Southeast column applies.

EquipmentTexas minimumApplies by
Split AC under 45,000 Btu/h14.3 SEER2Installation date, since January 1, 2023
Split AC 45,000 Btu/h and up13.8 SEER2Installation date, since January 1, 2023
Split heat pump14.3 SEER2 and 7.5 HSPF2Manufacture date, since January 1, 2023

No EER2 minimum applies in Texas because the EER2 rule covers only the Southwest states of Arizona, California, Nevada, and New Mexico. In the South, the U.S. Department of Energy says split ACs installed on or after January 1, 2023 must meet the new standard, with no delays or exemptions. Heat pumps go by manufacture date. Before 2023, the Texas minimum for a split AC was 14 SEER.

SEER and SEER2 side by side

NAHB’s table, credited to AHRI, lines up 14.3 SEER2 with about 15.0 SEER and 13.8 SEER2 with about 14.5 SEER. A heat pump rated 14.3 SEER2 and 7.5 HSPF2 lines up with about 15.0 SEER and 8.8 HSPF. The U.S. Department of Energy cautions that the new ratings are similar to the old ones but aren’t directly comparable.

Higher ratings, ENERGY STAR, and rebates

ENERGY STAR stopped certifying central air conditioners on February 1, 2026, so only heat pumps carry the label now. ENERGY STAR’s criteria for split-system heat pumps are at least 15.2 SEER2, 11.0 EER2, and 7.8 HSPF2.

Austin Energy’s AC rebate tiers start at 15.2 SEER2 and 12.0 EER2 ($600) and top out at 18.0 SEER2 and 13.0 EER2 ($800). Austin Energy’s heat pump rebate tiers run from $650 to $950. Our rebates guide lists every tier and the rules.

The refrigerant change

Under EPA’s Technology Transitions rule, new home AC and heat pump systems made or imported from January 1, 2025 must use a refrigerant with a global warming potential under 700. That moved new equipment from R-410A, listed at 2,088 in EPA’s reference table, to R-454B at 465 and R-32 at 675. Both are ASHRAE class A2L refrigerants, described as having “lower flammability” in Rheem’s installation instructions.

EPA’s May 2026 final rule, effective July 27, 2026, removed the January 1, 2026 installation deadline, so R-410A systems built or imported before 2025 can be installed until supply runs out. Parts used to repair existing systems aren’t restricted. U.S. production and import of R-22 ended January 1, 2020, and existing R-22 systems can keep running.

Matched systems and line sets

AHRI certifies a split system’s performance as a pairing, and each certified pairing gets its own reference number. Under the U.S. Department of Energy’s 10 CFR 430.32, an outdoor unit can’t be installed in the South if any of its certified pairings falls below the regional standard.

Rheem’s R-454B instructions say to use only indoor coils approved for R-454B. They also say an old R-410A or R-22 line set must be purged and flushed with nitrogen before reuse, and they recommend replacing it. Some newer coils, including certain Lennox models, ship ready for R-410A and convert to R-454B with a kit.

Sizing

ACCA’s Manual J is the national ANSI-recognized standard for calculating a home’s heating and cooling loads, and Manual S covers choosing equipment to meet those loads. Austin’s 2024 residential code, effective July 10, 2025, requires heating and cooling equipment to be sized by Manual S from Manual J loads, and Austin’s energy code applies that requirement to new equipment in an alteration. The calculation sizes equipment for an outdoor summer design temperature, which ACCA’s design table lists as 98°F for Camp Mabry, Austin’s official weather station. Austin Energy’s rebate requires Manual J or its own sizing guidance.

Permits in Austin

The City of Austin issues a stand-alone Mechanical Change Out permit for change-out work that needs no plan review. The City issues trade permits to a state-licensed contractor registered with the City or to a qualifying homeowner under a Homestead Permit. An activated permit expires on the 181st day if the work hasn’t been scheduled or inspected, and the job closes with a final inspection.

Austin’s energy code requires a duct leakage test on an alteration only when 25 percent or more of the registers or ductwork are relocated or the duct length grows 25 percent or more. The leakage limit is 12.0 cubic feet per minute per 100 square feet of floor area. For sellers, Austin’s Energy Conservation Audit and Disclosure ordinance covers homes 10 years old or older inside Austin city limits and the Austin Energy service area, and the audit includes the HVAC system and ducts.

Permits around Austin

The suburbs set their own rules.

  • Cedar Park lists heating and air conditioning equipment among projects that need a permit.
  • Georgetown requires a permit to install, repair, or replace a mechanical or gas system, including in parts of its extraterritorial jurisdiction (ETJ) where the City provides water, wastewater, or electric service.
  • Pflugerville lists AC replacement among its trade inspections and asks for Manual J and Manual S documents when permitting a unit replacement. It asks for Manual D only when ducts are replaced.
  • Round Rock issues a stand-alone HVAC trade permit for $50.

Licensing

Texas Occupations Code section 1302.251 says a person may not do air conditioning and refrigeration contracting without a state ACR contractor license, though a homeowner working on a home they solely own is exempt. You can check any license through the TDLR license search.

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