R513A Refrigerant44/56 R134a/R1234yf · Opteon XP10 · A1 R134a-class alternative
R513A is a near-azeotropic A1 blend of 44% R134a and 56% R1234yf by mass. It was developed as a lower-GWP alternative to R134a for chillers, medium-temperature refrigeration and selected air-conditioning or process applications. Its EPA GWP of 630 is below the 700 limit used for many U.S. chiller categories, while its A1 safety class can simplify retrofit and machinery-room decisions compared with A2L alternatives.
What is R513A refrigerant?
R513A combines the familiar pressure range of R134a-class equipment with substantially lower direct GWP. Chemours describes it as an azeotropic / near-azeotropic blend with negligible temperature glide, and EPA lists it as acceptable in several refrigeration, chiller and industrial-process end uses. It can be a practical R134a retrofit option, but compressor approval, capacity, expansion device, charge and lubricant still need to be checked.
R513A 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 | R513A | ASHRAE designation / Chemours Opteon XP10 |
| Nominal composition | R134a/R1234yf = 44/56 mass % | Chemours retrofit guidance |
| Refrigerant type | Near-azeotropic HFC/HFO blend | Two components |
| ODP | 0 | No ozone depletion |
| 100-year GWP | 630 | EPA Technology Transitions calculated value |
| Older published GWP | 631 AR4 / 573 AR5 | Chemours product literature |
| Safety classification | A1 | Lower toxicity / no flame propagation |
| Average molecular weight | ≈108.4 g/mol | Chemours property data |
| Normal boiling point | ≈ −28.0°C | Chemours property data |
| Temperature glide | Negligible / very small | Near-azeotropic behavior |
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 R513A 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.
Centrifugal & positive-displacement chillers
EPA SNAP lists R513A as acceptable and its GWP 630 fits the 700 limit used for many current chiller categories.
Medium-temperature commercial refrigeration
A major R134a-class transition application, including systems where nonflammable A1 refrigerant is preferred.
Industrial process refrigeration
EPA SNAP lists R513A as acceptable in new and retrofit industrial-process refrigeration.
Industrial process air conditioning
R513A is an accepted A1 option in EPA SNAP listings.
Refrigerated transport
EPA SNAP lists R513A as acceptable in refrigerated transport.
Self-contained residential/light-commercial AC
EPA Acceptability Determination 39 added R513A for new self-contained equipment only; that does not mean every split system can use it.
Continue through the Refrigerant Replacements and Low-GWP Refrigerants hubs for broader selection context.
R513A vs R134a: why the retrofit can be relatively straightforward
Chemours developed R513A specifically around R134a-class systems. The blend has similar pressure behavior, A1 classification and negligible glide, so many existing R134a components can remain technically relevant.
That does not make every conversion automatic. The retrofit procedure still calls for checking the compressor, leak condition, oil, filter-drier, charge, expansion control and final operating data.
R513A is therefore better described as a qualified R134a retrofit option than as a universal drop-in refrigerant.
Why R513A is A1 even though 56% of the blend is R1234yf
Pure R1234yf is A2L, but refrigerant safety classification applies to the finished mixture. R513A’s 44% R134a fraction changes the finished blend’s flammability behavior enough that R513A is classified A1.
This matters for equipment design because a component mixture cannot be classified by simply averaging the labels of its ingredients.
Leak detectors, SDS documents and machinery-room decisions should reference R513A itself rather than assuming pure-R1234yf behavior.
Why you may see R513A GWP 573, 630 or 631
Chemours literature commonly shows AR4 GWP 631 and AR5 GWP 573. EPA Technology Transitions currently uses a calculated GWP of 630 for regulatory purposes.
The apparent disagreement comes from different atmospheric-assessment datasets and regulatory calculation bases, not from different R513A compositions.
For U.S. Technology Transitions compliance, use the EPA value specified in 40 CFR 84.64 and the current EPA reference table.
R513A and the U.S. 700-GWP chiller threshold
EPA’s 2026 restrictions use a 700-GWP limit for comfort-cooling chillers and several industrial-process chiller categories. At GWP 630, R513A fits below that threshold.
That does not mean R513A fits every refrigeration sector. Some non-chiller industrial-process and future retail-food categories use limits of 150 or 300, which are far below 630.
Always match the refrigerant to the exact EPA subsector rather than treating 'below 700' as a site-wide approval.
R513A vs R134a
The table highlights engineering differences rather than implying direct interchangeability.
| Characteristic | R513A | R134a |
|---|---|---|
| Type | Near-azeotropic HFC/HFO blend | Pure HFC |
| Composition | 44% R134a / 56% R1234yf | 100% R134a |
| EPA GWP | 630 | 1,430 |
| Safety class | A1 | A1 |
| Temperature glide | Negligible | None |
| Primary modern role | Lower-GWP A1 retrofit/new equipment | Legacy installed base |
| U.S. 700-GWP chiller limit | Below | Above |
R513A safety: A1 does not mean zero leak or pressure risk
R513A is classified A1, so lower flammability is not the defining design issue. Large releases can still displace oxygen, liquid refrigerant can cause frostbite, and high-temperature work can generate hazardous decomposition products. Chiller and machinery-room applications must consider total charge, ventilation and pressure relief.
Oxygen displacement
Large releases in enclosed machinery rooms can reduce breathable oxygen.
Cold liquid
Charging and recovery can expose technicians to flashing liquid and frostbite.
Blend identity
Prevent cross-contamination with R134a or other similar-pressure refrigerants.
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.
R513A refrigerant leak detection
Validate detector response to the finished blend
Use portable or fixed detection validated for the finished R513A blend. GasNose recommends R513A-specific infrared area monitoring, compatible service leak detectors and refrigerant identification where mixing with R134a is possible. A detector calibrated only for one component should not automatically be assumed equivalent.
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 R513A in 2026
United States
EPA lists R513A as acceptable in centrifugal and positive-displacement chillers, industrial process refrigeration, refrigerated transport and other selected end uses. Technology Transitions uses GWP 630, below the 700 limit applied to many chillers. EPA Acceptability Determination 39 also listed R513A for new self-contained residential/light-commercial AC and heat-pump equipment; that listing does not extend to every system architecture.
European Union
R513A has lower GWP than R134a but remains a fluorinated blend above 150. EU Regulation 2024/573 therefore gives it a more transitional role than sub-150 or non-fluorinated refrigerants in equipment categories with progressively tighter limits.
Is R513A being phased out?
R513A is a useful A1 transition refrigerant, especially for R134a-class equipment. It is better positioned than R134a under 700-GWP rules, but it is not future-proof in sectors moving to 150/300 or non-fluorinated requirements.
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 R513A?
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 R513A
“R513A GWP is definitely 573.”
573 is a common AR5 value; current EPA Technology Transitions uses 630.
“Because it contains R1234yf, R513A must be A2L.”
The finished R513A blend is classified A1.
“R513A can replace R134a without checking the machine.”
Retrofit still requires compressor/OEM and component review.
“GWP 630 means R513A fits every U.S. refrigeration application.”
Some current and future subsectors use 150 or 300 limits.
R513A refrigerant FAQ
Concise answers to common composition, retrofit, glide, safety and regulation questions.
What is R513A?
What is the EPA GWP of R513A?
Why do some data sheets show 573 or 631?
Is R513A flammable?
Does R513A have temperature glide?
Can R513A replace R134a?
Is R513A used in chillers?
Does R513A fit the U.S. 700-GWP chiller limit?
Can R513A be used in residential AC?
How should R513A leaks be detected?
R513A 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 R513A 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.