Last reviewed: September 2026 · By the HVAC Brief Editorial Team · Our sourcing and editorial standards
80% of ENERGY STAR certified heat pump combinations now use R-454B, an A2L refrigerant that barely existed in US residential equipment before 2025.
That number depends heavily on what you count. By distinct outdoor models, R-454B is 43% and R-32 rises from 2% to 22%. Most published figures on the transition do not say which they are counting.
The refrigerant transition is usually described from the regulation down: what EPA restricted and when. The ENERGY STAR certified product list lets it be described from the products up, by counting what manufacturers have actually certified. The list held 285,055 heat pump combinations when this analysis was run, each with its refrigerant recorded.
The headline, two ways
| Refrigerant | Certified combinations | Share | Distinct outdoor models | Share |
|---|---|---|---|---|
| R-454B | 229,095 | 80.4% | 3,727 | 43.3% |
| R-410A | 50,360 | 17.7% | 2,949 | 34.3% |
| R-32 | 5,600 | 2.0% | 1,928 | 22.4% |
By certified combinations, R-454B is 80.4% of the market. By distinct outdoor models it is 43.3%. R-32 is 2.0% by one measure and 22.4% by the other. Neither is wrong. They answer different questions.
Why the counts diverge
ENERGY STAR certifies heat pumps as matched systems: a specific outdoor unit with a specific indoor coil or air handler, each pairing with its own AHRI reference number and rating. A ducted outdoor unit can be matched to dozens of indoor units. A ductless outdoor unit is usually matched to one or a few heads.
| Product type | Refrigerant | Outdoor models | Combinations | Combinations per model |
|---|---|---|---|---|
| Split system | R-454B | 1,596 | 221,051 | 138.5 |
| Split system | R-410A | 786 | 43,028 | 54.7 |
| Split system | R-32 | 285 | 2,277 | 8.0 |
| Mini or multi split | R-454B | 2,225 | 7,813 | 3.5 |
| Mini or multi split | R-410A | 2,158 | 7,155 | 3.3 |
| Mini or multi split | R-32 | 1,421 | 2,876 | 2.0 |
| Single package | R-454B | 84 | 231 | 2.8 |
| Single package | R-410A | 64 | 177 | 2.8 |
| Single package | R-32 | 238 | 447 | 1.9 |
R-454B split systems average 139 certified combinations per outdoor model, against 55 for R-410A and 8 for R-32. That single fact explains most of the gap. R-454B dominates ducted split systems, and ducted split systems generate enormous numbers of combinations, so any combination count is pulled toward R-454B.
Among split systems alone, counted by outdoor model, R-454B is 60%, R-410A 29% and R-32 11%. In mini and multi splits the three refrigerants are much closer, and in single-package units R-32 leads.
The transition by certification year
| Year certified | Combinations | R-454B | R-410A | R-32 |
|---|---|---|---|---|
| 2025 | 77,547 | 69.0% | 30.3% | 0.8% |
| 2026 | 206,649 | 84.8% | 12.8% | 2.4% |
Among combinations certified in 2026, R-454B is 85%, up from 69% among those certified in 2025. R-410A’s share fell from 30% to 13%.
A certification date is not a manufacturing date. Products are certified to the current ENERGY STAR specification, so the list concentrates in recent years by construction and does not show when any unit was built. It shows what is available to certify now.
R-410A has not disappeared, and that is lawful
R-410A remains 18% of certified combinations and 34% of outdoor models. Federal rules at 40 CFR 84.54 have barred the manufacture or import of new residential and light commercial systems using refrigerant with a global warming potential of 700 or more since January 1, 2025. EPA’s final rule at 91 FR 31284, effective July 27, 2026, allows equipment made or imported before that date to continue to be installed, with no end date. The certified list reflects that inventory. Our explainer on whether R-410A can still be installed sets out the rule, and the dates are in our HVAC compliance deadline registry.
Frequently asked questions
What refrigerant do new heat pumps use?
Mostly R-454B. Of 285,055 ENERGY STAR certified heat pump combinations, 80.4% use R-454B, 17.7% use R-410A and 2.0% use R-32. Counted by distinct outdoor models instead, the split is 43.3%, 34.3% and 22.4%.
Why do the two counts differ so much?
Because ENERGY STAR certifies matched combinations of an outdoor unit and an indoor coil or air handler. A ducted split system outdoor unit is matched to many indoor units: R-454B split systems average 139 certified combinations per outdoor model. Mini splits average two or three. So counting combinations heavily weights ducted R-454B systems.
Which count should I use?
It depends on the question. Combinations approximate how many distinct installable systems are available, which is closest to what a homeowner chooses between. Outdoor models approximate how many products manufacturers are building. A figure quoted without saying which is not interpretable.
Is R-410A banned?
Not for installation. Since January 1, 2025, federal rules bar manufacturing or importing new residential and light commercial air conditioning and heat pump systems using refrigerant with a global warming potential of 700 or more, which includes R-410A. EPA’s final rule of May 26, 2026 allows equipment manufactured or imported before that date to continue to be installed, with no end date.
Why are R-410A models still being certified in 2026?
The ENERGY STAR list records 26,499 R-410A combinations with a 2026 certification date. A certification date is when a product was certified to the current ENERGY STAR specification, not when it was manufactured, and federal rules allow pre-2025 R-410A inventory to be installed. Nothing in the list indicates when any unit was built.
What is the difference between R-454B and R-32?
Both are A2L refrigerants, meaning lower toxicity and mildly flammable, and both have a global warming potential under 700. R-454B is a blend; R-32 is a single compound. US manufacturers split between them, and the certified list shows R-454B dominant in ducted systems.
Does the refrigerant affect efficiency?
The certified data does not show a large difference. Median heating capacity retention at 5°F is similar across the three refrigerants in our cold-climate analysis. Refrigerant choice is driven mainly by regulation and manufacturer strategy.
How many manufacturers make R-454B heat pumps?
107 ENERGY STAR partners have at least one R-454B heat pump certified, against 99 for R-410A and 80 for R-32. A partner can certify products under more than one refrigerant.
Methodology and limitations
- Source: ENERGY STAR Certified Heat Pumps dataset (data.energystar.gov, dataset 83eb-xbyy), retrieved October 2026. Aggregates were computed by the dataset’s own query service.
- Unit of count: the list holds 285,055 matched outdoor-indoor combinations. Distinct outdoor models are counted as distinct outdoor model numbers per refrigerant. A model number listed under more than one product type is counted once per refrigerant.
- Refrigerant is the field ENERGY STAR records for each combination. The list contains three refrigerants: R-454B, R-410A and R-32.
- Certification year is the year of the date_certified field. It reflects certification to the current ENERGY STAR specification, not the manufacturing or first-sale date, which is why recent years dominate.
- ENERGY STAR certified products are a subset of the market: products that meet ENERGY STAR criteria and whose makers chose to certify. Shares here describe the certified market, not all heat pumps sold.
- Combinations are not sales. A product with many certified matches is not necessarily sold more often.
- No manufacturer is ranked. The count of partners per refrigerant is reported only to show breadth of adoption.
Sources
- ENERGY STAR, Certified Heat Pumps dataset.
- Code of Federal Regulations, 40 CFR 84.54.
- US Environmental Protection Agency, Phasedown of Hydrofluorocarbons: Reconsideration of Certain Regulatory Requirements, 91 FR 31284, May 26, 2026.
The HVAC Brief is an independent trade publication. We do not sell equipment, take manufacturer advertising, or accept payment for placement in our research. Corrections welcome.
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