R457A RefrigerantA2L low-GWP blend · sub-150 profile · refrigeration and selected AC/heat-pump listings
R457A is a low-GWP A2L refrigerant blend based on R32, R1234yf and R152a. It is one of the newer sub-150 fluorinated refrigerants that can satisfy stricter climate thresholds while still offering practical cooling performance. Because it is A2L and zeotropic, it must be treated as a purpose-designed refrigerant rather than a generic field replacement for older A1 systems.
What is R457A refrigerant?
R457A is best understood as a modern sub-150 A2L platform. EPA’s current GWP reference is 137. U.S. SNAP actions have listed R457A in new residential/light-commercial AC and heat pumps, and later also in multiple commercial and industrial refrigeration end uses subject to use conditions. That combination makes it more important than many obscure refrigerant numbers because it appears in both HVAC and refrigeration transition discussions.
R457A refrigerant properties
Use these values for research and screening. For equipment design, charging and compliance, use the exact supplier PT data, SDS, OEM documentation and regulation that governs the project.
| Property | Reference | Engineering / source note |
|---|---|---|
| Designation | R457A | ASHRAE designation |
| Nominal composition | R32 / R1234yf / R152a ≈ 18 / 70 / 12 | Published technical literature |
| Refrigerant type | Zeotropic HFC/HFO blend | Three components |
| ODP | 0 | No ozone depletion |
| 100-year GWP | 137 | EPA Technology Transitions |
| Older GWP references | ≈139–154 in older literature | Assessment basis differs |
| Safety classification | A2L | Lower flammability |
| Temperature glide | Moderate blend glide | Use exact PT chart |
| Primary positioning | Low-GWP refrigeration / selected AC uses | Sub-150 pathway |
| Key differentiator | Below 150 GWP with practical system performance | Important regulatory milestone |
EPA Technology Transitions uses the values shown on this page. Older product literature may use IPCC AR4/AR5 or another assessment, so a different number is not automatically an error.
Where is R457A used?
Applications must be evaluated by system type, charge, compressor, heat exchanger, safety class and current regulation. The examples below describe recognized use contexts, not automatic approval for every installation.
Residential & light-commercial AC / heat pumps
EPA Rule 23 listed R457A as acceptable subject to use conditions in new equipment.
Commercial refrigeration
EPA Rule 26 added R457A to several new commercial and industrial refrigeration categories.
Cold storage / remote condensing / supermarket systems
R457A is relevant where a sub-150 A2L option is desired.
Industrial process refrigeration
EPA lists it subject to use conditions in new equipment.
Commercial ice machines
Rule 26 includes R457A among acceptable new-equipment refrigerants subject to use conditions.
Transition planning
Frequently evaluated as one of the lower-GWP A2L candidates when 150-GWP thresholds matter.
Continue through the Refrigerant Replacements and Low-GWP Refrigerants hubs for broader selection context.
Why R457A matters more than many little-known refrigerants
Some refrigerants are technically listed but rarely relevant in the real market. R457A is different because it combines a current EPA GWP of 137 with a broad regulatory storyline.
EPA Rule 23 placed it in new residential and light-commercial AC / heat pumps, while Rule 26 later added it across several commercial and industrial refrigeration categories.
That makes R457A useful for GEO and technical education because it sits at the intersection of stricter climate policy and practical equipment transition.
R457A is not just another R404A or R410A 'replacement label'
The blend composition and A2L safety class mean R457A should not be reduced to a one-line 'replaces X' claim. Its real engineering value is that it can meet sub-150 GWP thresholds where older A1 blends cannot.
In practice, system suitability depends on compressor design, charge size, application temperature, discharge temperature and A2L safeguards.
That is why high-quality content should discuss regulatory role and safety architecture, not just headline GWP.
Why the R152a fraction matters
R457A uses R32 and R1234yf as the dominant climate-performance platform, while R152a helps tune thermodynamic and flammability behavior.
R152a itself is a flammable refrigerant component, so the finished blend remains A2L rather than A1.
Technicians and detector suppliers should therefore validate for the finished blend, not assume that response to one component automatically represents the complete refrigerant.
Below 150 GWP does not automatically mean 'future-proof everywhere'
R457A’s EPA GWP of 137 gives it an important advantage wherever 150 is a hard numerical threshold, especially in parts of commercial refrigeration.
But refrigerant regulation is never just one number. End-use listings, use conditions, regional rules, codes and equipment standards still control whether a refrigerant is practical in a given project.
A2L acceptance, service readiness and OEM support will determine whether R457A becomes common in a given segment.
R457A vs R455A
The table highlights engineering differences rather than implying direct interchangeability.
| Characteristic | R457A | R455A |
|---|---|---|
| EPA GWP | 137 | 146 |
| Safety class | A2L | A2L |
| Blend family | R32/R1234yf/R152a | R744/R32/R1234yf |
| Sub-150 | Yes | Yes |
| Typical role | New low-GWP HVAC/R candidate | Commercial refrigeration focus |
| Phase behavior | Zeotropic | Zeotropic |
| Selection angle | Broad transition relevance | Cold-chain / refrigeration relevance |
R457A safety: sub-150 climate performance still comes with A2L obligations
R457A is A2L. Even though it is much less flammable than A3 hydrocarbons, it still requires equipment design, servicing procedures, ventilation and component selection appropriate for lower-flammability refrigerants. Existing A1 equipment should not be assumed suitable for R457A unless explicitly approved.
A2L classification
System design and service must follow applicable lower-flammability standards.
Blend handling
Use correct PT data and charge as a blend.
Detector validation
Use leak detection validated for the finished refrigerant, not only a component gas.
Actual risk depends on charge, release rate, pressure, room volume, ventilation, ignition sources, equipment construction, alarm logic and service condition.
See the Refrigerant Safety Guide for classification context.
R457A refrigerant leak detection
Validate detector response to the finished blend
Use fixed or portable leak detection validated for R457A or its finished A2L blend behavior. Detector suitability depends on the required function: equipment mitigation, machinery-room monitoring and service leak finding are not interchangeable tasks. The GasNose refrigerant gas library is a useful starting point for refrigerant detection research.
Portable service leak detectors, fixed area monitors, A2L mitigation sensors and refrigerant identifiers perform different functions. Define the alarm action and concentration range before selecting the technology.
Regulatory position of R457A in 2026
United States
EPA Technology Transitions uses GWP 137 for R457A. EPA SNAP Rule 23 listed it as acceptable subject to use conditions in new residential and light-commercial AC and heat pumps, and Rule 26 later added it to multiple commercial and industrial refrigeration end uses. As always, the exact end-use listing and use conditions control the compliance decision.
European Union
Because R457A is below 150 GWP, it aligns numerically with tighter low-GWP direction in parts of the EU market. However, it remains a fluorinated A2L blend, so safety standards and application-specific restrictions still matter.
Is R457A being phased out?
R457A is not a classic high-GWP transition refrigerant. Its long-term value depends more on A2L adoption, OEM support and regional fluorinated-gas strategy than on a near-term phaseout driven by direct GWP alone.
U.S. refrigeration limits differ by cold storage, supermarket, remote condensing, stand-alone product, industrial process and chiller category. A refrigerant may fit one pathway and fail another.
Use the Refrigerant Regulations Hub for regional research.
What should be compared with R457A?
Compare the real equipment pathway: retrofit vs new system, A1 vs A2L capability, GWP threshold, glide, compressor envelope, energy efficiency and service ecosystem.
Practical misconceptions about R457A
“R457A is too obscure to matter.”
Its combination of EPA GWP 137 and broad SNAP relevance makes it much more important than many niche refrigerants.
“Below 150 means any system can use it.”
A2L use conditions, equipment design and end-use-specific approvals still apply.
“It is just a renamed retrofit for one legacy refrigerant.”
R457A should be viewed as a new-system transition candidate, not a generic one-line retrofit answer.
“A detector for R32 or R152a alone is automatically enough.”
Finished-blend validation is still important.
R457A refrigerant FAQ
Concise answers to common composition, retrofit, glide, safety and regulation questions.
What is R457A?
What is the EPA GWP of R457A?
Is R457A below 150 GWP?
Is R457A flammable?
Where is R457A used?
Is R457A a pure refrigerant?
Can R457A be treated as a generic retrofit?
Why is R457A worth covering?
What refrigerants is R457A often compared with?
How should R457A leaks be detected?
R457A sources and further reading
This profile uses current EPA regulatory references plus refrigerant supplier, NIST, scientific and GasNose resources. Re-check the latest edition before design or compliance decisions.
Working with R457A or planning a refrigerant transition?
Compare GWP, safety class, temperature glide, equipment compatibility and regulatory lifetime before selecting a refrigerant.
Technical Notice: This page is for refrigerant research and general technical reference. Refrigerant suitability, permitted charge, equipment approval, leak mitigation, servicing procedures and regulatory compliance depend on the exact equipment, installation and jurisdiction. Always verify current manufacturer documentation, SDS, applicable standards and local regulations before selecting, replacing, charging or servicing a refrigerant.