R-32 PT Chart and Refrigerant Profile

Where you will find R-32

R-32 (difluoromethane, HFC-32) is one of the two main refrigerants in new US residential and light commercial AC and heat pumps built since the 2025 low-GWP rule, alongside R-454B. It is common in ductless mini-splits and also used in heat-pump water heaters and scroll chillers (Arkema).

You already know the molecule. R-32 is half of R-410A by mass and more than two-thirds of R-454B. As a pure refrigerant it runs at pressures close to R-410A but slightly higher across the range.

Identify it from the nameplate and the A2L flammability markings on the unit. New cylinders are light green-gray (RAL 7044) with a red band on the shoulder or top for a flammable refrigerant. The legacy label color for R-32 is light blue-green. Equipment carries the leak detection or other mitigation that the UL 60335-2-40 based SNAP use conditions require; see refrigerant detection systems.

Charging R-32

R-32 is a single-component refrigerant, so it has no glide and does not fractionate. Vapor charging will not change its composition, a leak does not leave an off-ratio charge behind, and recovered R-32 stays R-32. Even so, follow the equipment maker’s method: the Danfoss VZF application guide calls for the initial charge in liquid phase at the condenser outlet or filter-drier (Danfoss).

With one saturation temperature per pressure, the same column serves the suction and liquid sides.

• Fixed orifice: charge to target superheat from CEC Title 24 Table RA3.2-2 (installer tolerance ±5°F, valid at 55–115°F outdoor, return dry bulb of 70°F or more, return wet bulb of 76°F or less). Use the target superheat calculator and the superheat calculator.
• TXV or EEV: charge by subcooling to the nameplate or manual target (Title 24 installer tolerance ±3°F) with the subcooling calculator.

Charges are small. Arkema says a typical R-32 charge is about 30% less than R-410A for the same duty (Arkema). A few ounces of error is a bigger share of the total, so weigh refrigerant in with a scale and use the manual’s line-set adder (line-set charge calculator).

Gauges and hoses must be rated for R-32 pressures. Manifolds and digital gauges need R-32 in their refrigerant list to give correct saturation temperatures.

Oil and compatibility

R-32 compressors use POE oil. Copeland lists POE-46 (with approved alternates) for its R-32 compressors (Copeland AE 93-11), and Danfoss specifies POE 185SL for its VZF line. The viscosity grade differs from typical R-410A POE-32, so add only the oil named on the compressor label or in the manual.

POE is hygroscopic. Keep the system closed, replace the filter-drier whenever you open it, and evacuate to the OEM target, typically 350–500 microns (evacuation guide). R-32 is not a retrofit for R-22 or R-410A equipment: A2L refrigerants need equipment designed and listed for them.

Safety, handling and recovery

R-32 is ASHRAE class A2L: lower toxicity, mildly flammable, burning velocity of 10 cm/s or less (flammability classes explained). Keep ignition sources out of the work area and follow the A2L service steps in the installation manual.

Use a recovery machine certified for flammable refrigerants. Under 40 CFR 82.158 that means Appendix B4, which adds UL 1963 Supplement SB to AHRI 740 (recovery machine compatibility). Many A2L cylinders use left-hand thread valves, an industry practice not specified in Guideline N-2017, so carry the right adapter.

R-32 sits just over the Section 608 pressure line. Its computed saturation pressure at 104°F is 359.4 psia (344.8 psig), above the 355 psia cutoff, so by the 40 CFR 82.152 definition R-32 equipment is very high pressure, while R-410A and R-454B are high pressure. Type II (or Universal) certification covers both classes, and Type I covers factory-sealed units of 5 lb or less. Very-high-pressure appliances must be recovered to 0 in Hg.

Status and replacements

R-32 has a GWP of 675 (AR4), below the 700 limit in the Technology Transitions rule. That makes it compliant for new residential and light commercial AC and heat pumps (from Jan 1 2025), VRF (from Jan 1 2026) and comfort chillers. EPA accepted R-32 subject to use conditions in residential and light commercial AC in SNAP Rule 23 (May 6 2021), and in chillers, residential dehumidifiers and room AC in SNAP Rule 25 (Apr 28 2023). A proposed SNAP Rule 27 (Nov 10 2025) would update use conditions but was not final as of Oct 21 2026.

R-32 is an HFC, so it counts against the AIM Act allowance phasedown: 60% of baseline in 2024–2028, 30% in 2029–2033, 20% in 2034–2035 and 15% from 2036. No successor has been set. Compare it with the other options in R-410A vs R-32, R-454B vs R-32 and the A2L refrigerants guide.

Common questions

Is R-32 flammable?

Yes, mildly. It is class A2L: it can ignite at a high enough concentration, but its burning velocity is 10 cm/s or less and its lower flammability limit is above 0.10 kg/m³, unlike class 3 refrigerants such as propane.

What oil does R-32 use?

POE. Copeland lists POE-46 and Danfoss POE 185SL for their R-32 compressors, so check the compressor label for the grade.

Can R-32 replace R-22?

Not in an existing R-22 system. R-32 needs A2L-rated equipment and runs at far higher pressure. For retrofit options see R-22 replacement refrigerants.