R-513A PT Chart and Refrigerant Profile

Where you will find R-513A

R-513A is the lower-GWP stand-in for R-134a in stationary equipment. It is an azeotrope of 56% R-1234yf and 44% R-134a, sold mainly as Chemours Opteon XP10. Look for it in medium-temperature reach-ins, walk-ins and process refrigeration. It also shows up in centrifugal and screw chillers, heat pumps, vending and beverage machines, ice rinks and the medium-temperature stage of cascade systems.

You meet it two ways. Newer equipment ships with it from the factory: EPA SNAP lists R-513A as acceptable in centrifugal chillers and household refrigerators since July 16 2015. Older R-134a systems may have been retrofitted, so check for a retrofit tag on the unit. Some R-12 service-blend systems that ran R-401A or R-409A have been converted too. The legacy cylinder color was sky blue; new cylinders are light green-gray like every other refrigerant.

Charging R-513A

R-513A is an azeotrope. At the nominal composition its bubble and dew points are essentially the same (the computed glide at 40°F is 0.03°F), so one PT column serves both sides in practice. The table above still shows both columns.

Chemours still says to remove it from the cylinder as liquid only. Throttle it into the system so it enters as vapor, and do not dump liquid into the suction line.

Charge to the equipment manufacturer’s method. Fixed-restriction systems follow the OEM superheat data; the target superheat calculator applies only where that method fits. TXV and EEV systems are charged by subcooling to the nameplate target with the subcooling calculator.

For an R-134a retrofit, Chemours’ retrofit guidelines start with about 85% of the original R-134a charge by weight. They add refrigerant until the system runs to spec, typically ending around 97% of the original charge. Treat those figures as Chemours’ starting points, not targets.

Oil and compatibility

R-513A runs on POE. Copeland lists POE-32 for its compressors on R-513A. Chemours says the POE already in most R-134a systems is suitable.

Systems that ran HCFC service blends such as R-401A or R-409A are different. They used mineral oil or alkylbenzene, so Chemours calls for an oil change to POE when retrofitting them to R-513A. Follow the compressor maker’s procedure for how much old oil must come out. The oil types guide has the background.

Safety, handling and recovery

R-513A is ASHRAE class A1: lower toxicity, no flame propagation. That holds even though its R-1234yf component is A2L on its own. The blend as formulated is classified A1.

It is a medium-pressure refrigerant under 40 CFR 82.152, so Type II certification applies (Type I for small appliances; Universal covers both). Venting is prohibited, and since Jan 1 2018 sales are limited to certified technicians under 82.154(c).

Required recovery for medium-pressure appliances made on or after Nov 15 1993 is 10 in Hg below 200 lb charge and 15 in Hg at 200 lb or more. Small appliances need 90% recovery with the compressor running, 80% with it not running, or 4 in Hg. As a non-flammable refrigerant it is recovered with machines certified under 40 CFR 82.158 Appendix B3 (AHRI 740-2016).

Because R-513A contains an HFC, the Emissions Reduction and Reclamation rule applies to it. Appliances with 15 lb or more of HFC need leak repair from Jan 1 2026; residential and light commercial AC and heat pumps are excluded. From Jan 1 2029, supermarket systems, refrigerated transport and automatic commercial ice makers must be serviced with reclaimed refrigerant.

Status and replacements

Its R-134a content makes R-513A a blend containing a regulated HFC. The AIM Act allowance schedule therefore limits supply: 90% of baseline in 2022–2023, 60% in 2024–2028, 30% in 2029–2033, 20% in 2034–2035 and 15% from 2036.

Under Technology Transitions (40 CFR 84.54), EPA computes its GWP as 629.8. That is below the 700 limit, so R-513A is allowed in new comfort-cooling chillers manufactured from Jan 1 2025. It is above the 150 and 300 limits that apply to new household refrigerators, stand-alone retail units and vending machines. Hydrocarbons such as R-290 and R-600a are the usual alternatives there.

R-513A is itself the replacement in this family; the sources used here list no successor. For choosing between it and the other R-134a alternatives, see the R-134a replacement guide. For chillers, R-1234ze(E) is the other common option.

Common questions

Is R-513A a drop-in for R-134a?

Chemours publishes it as an R-134a retrofit refrigerant: in most R-134a systems the existing POE stays, and you recharge starting at about 85% of the old weight. It is still a retrofit, so recover the R-134a fully, follow the compressor maker’s approval list and relabel the system.

What oil does R-513A use?

POE. Systems coming from R-134a usually keep their POE. Systems coming from mineral-oil or alkylbenzene service blends need an oil change.