What R-410A is and where it is used
R-410A is a near-azeotropic blend of R-32 and R-125, 50/50 by weight. Arkema says it was developed to replace R-22 in many air conditioning applications, and that R-22 has not been permitted in new OEM equipment since 2010. Carrier, which calls it Puron, describes R-410A as the former industry standard. Arkema lists new residential and commercial air conditioning, heat pumps, dehumidifiers and small chillers as its uses. It is ASHRAE safety group A1 with zero ozone depletion potential and a 100-year GWP of 2088 (AR4) or 1924 (AR5).
R-410A runs at much higher pressure than R-22. At 40°F it reads 118.8 psig, against 68.6 psig for R-22, and Arkema puts typical operating pressures 50 to 60% higher. Arkema says equipment and components must be designed for those pressures, and that R-410A should never be used to retrofit an R-22 system.
How to read the R-410A chart
Read across from a temperature, or start from a gauge reading. Because R-410A is a blend, the chart lists a bubble (liquid) and a dew (vapor) pressure. The glide is tiny: at 118 psig the two saturation temperatures are only 0.2°F apart. Chemours' A/C guide uses the saturated vapor value for superheat and the saturated liquid value for subcooling.
- Superheat: use the dew column. A suction reading of 118 psig converts to 39.8°F. Honeywell's procedure reads pressure and line temperature at the same point at the evaporator outlet, then subtracts the saturation temperature from the measured temperature.
- Subcooling: use the bubble column. A liquid line reading of 400 psig converts to 116.4°F. Honeywell reads both at the condenser outlet and subtracts the measured temperature from the saturation temperature.
The superheat calculator and subcooling calculator do the lookup for you. For why blends have two columns, see bubble point, dew point and glide.
Example R-410A pressures on an air conditioner
Gauge pressures follow the saturation temperatures in the coils. The figures below are worked examples at assumed coil temperatures, not targets for any unit. Chemours compares A/C refrigerants at a 45°F average evaporator and a 115°F average condenser, so those temperatures are used here along with nearby values.
- Suction: at a 45°F evaporator dew point, R-410A reads 130.1 psig. At 40°F it reads 118.4 psig.
- Head: at a 115°F condensing (bubble) temperature, R-410A reads 392.3 psig. At 125°F it reads 448.0 psig.
Arkema tells users to check the equipment manufacturer's guidelines for charging instructions. Charge by the method and values in the unit's installation manual.
Service notes
- Oil: Arkema says R-410A is typically used with POE oil, because its HFC components do not mix with mineral oil or alkylbenzene. It warns that POE is hygroscopic and readily absorbs moisture from the air, and that high moisture levels can lead to oil degradation and system failure.
- Charging: Chemours says to remove refrigerant blends from the cylinder as liquid. Arkema notes that R-410A can be charged as vapor or liquid and defers to the equipment manufacturer. Follow the installation manual.
- Pressure ratings: Honeywell's AZ-20 chart says to use only service equipment and components designed for R-410A, and filter driers with a service pressure rating of at least 600 psig.
- No mixing: Chemours' PT guide says not to mix refrigerants, so never top off with a different one.
Replacements and regulations
EPA's Technology Transitions rule set a GWP limit of 700 for new residential and light commercial AC and heat pumps from January 1, 2025. R-454B (GWP 465) and R-32 (GWP 675), both A2L refrigerants, are under it, and Carrier markets R-454B as Puron Advance. At 40°F, R-454B dew is 107.0 psig and R-32 is 121.0 psig. Chemours states that A2L refrigerants can only be used in new equipment and are not to be used as retrofit refrigerants, so neither goes into an R-410A system. Compare them in R-410A vs R-454B and R-410A vs R-32, and see what A2L refrigerants change.
Existing systems are not affected. EPA says products and systems can be serviced and repaired throughout their useful life, and its May 2026 amendments let systems built from components made or imported before 2025 be installed until that supply runs out. The AIM Act phasedown also limits new HFC supply: EPA says production and consumption dropped to 60% of baseline in 2024 and will drop to 30% in 2029.