R-407C PT Chart and Refrigerant Profile

Where you will find R-407C

R-407C turns up in two places. The first is R-22 systems that were retrofitted as R-22 was phased out, from residential splits to commercial rooftops. The second is equipment built for R-407C, including some heat pumps, packaged units and non-flooded (DX) chillers. It is also used in medium-temperature refrigeration (Arkema).

On a retrofit, the nameplate may still say R-22. Look for a retrofit label naming R-407C and the oil used. The legacy cylinder color was medium brown; new cylinders are light green-gray (RAL 7044), so go by the label. Trade names include Freon 407C (formerly Suva 9000), Forane 407C, Klea 407C and Genetron 407C (Orbia).

R-407C pressures are close to R-22, far below R-410A, which is why it was used for R-22 retrofits. The two are not interchangeable with R-410A.

Charging R-407C

Charge liquid only. R-407C is a zeotropic blend of R-32, R-125 and R-134a with a large glide, and vapor drawn from the cylinder has the wrong composition. Arkema calls for liquid-phase charging, and Chemours allows topping off after a leak as long as the refrigerant goes in as liquid (Chemours bulletin). On an R-22 retrofit, Arkema suggests starting at about 90–95% of the original R-22 charge weight, then finishing to superheat or subcooling.

The glide is the thing to get right. At a 40°F dew point the glide is about 11.1°F; at 40°F this chart shows 63.2 psig dew and 80.2 psig bubble. Using one column for both readings puts your superheat or subcooling off by roughly the glide.

• Superheat: convert suction pressure with the dew column. On fixed-orifice systems, charge to target superheat from CEC Title 24 Table RA3.2-2 (±5°F for the installer, valid at 55–115°F outdoor, return dry bulb of 70°F or more, return wet bulb of 76°F or less) with the target superheat calculator.
• Subcooling: convert liquid-line pressure with the bubble column. TXV systems are charged by subcooling to the manufacturer target (±3°F for the installer) with the subcooling calculator.

The temperature glide calculator shows the glide at any pressure. Because the refrigerant warms as it boils through the evaporator, coil-inlet temperature reads lower than the dew-point saturation used for superheat. That is normal on R-407C.

Arkema does not recommend R-407C for flooded evaporators.

Oil and compatibility

R-407C needs POE oil. Chemours lists POE only, and Copeland approves POE-32 for R-407C (Copeland AE 93-11).

When retrofitting an R-22 system, Arkema calls for a complete oil change to POE (Arkema retrofit guide). Follow the compressor maker’s limit on residual mineral oil, replace the filter-drier, label the system with the new refrigerant and oil, and evacuate to the OEM target, typically 350–500 microns (evacuation guide). POE absorbs moisture, so keep containers closed. See the refrigerant oil guide.

Never mix R-407C with R-22 or another blend in the system or in a recovery cylinder.

Safety, handling and recovery

R-407C is ASHRAE class A1: lower toxicity and no flame propagation. Standard R-22-era gauges and hoses work at its pressures, but your manifold or digital gauge must have R-407C selected, with bubble and dew handled correctly.

Section 608 Type II (or Universal) certification covers R-407C systems, and the sales restriction applies. It is a high-pressure refrigerant under 40 CFR 82.152; its computed liquid saturation pressure at 104°F is 253.7 psia (239.0 psig, bubble). Recover appliances under 200 lb to 0 in Hg, and those of 200 lb or more to 10 in Hg.

From Jan 1 2026, HFC leak repair under 40 CFR 84.106 applies to appliances with 15 lb or more, but not to residential and light commercial AC and heat pumps. Large R-407C chillers and refrigeration systems can fall under it.

Status and replacements

R-407C is an HFC with a GWP of 1,774 (AR4). EPA lists it as acceptable in residential and light commercial AC. Under the Technology Transitions rule (40 CFR 84.54), self-contained residential and light commercial AC and heat pump products using refrigerants with a GWP of 700 or more cannot be manufactured or imported from Jan 1 2025, and new split systems at that GWP can be installed only if all their components were made or imported before Jan 1 2025 (VRF from Jan 1 2026). That puts R-407C under the same new-equipment limits as R-410A. Servicing existing R-407C systems and retrofitting R-22 systems with it remain legal.

Supply falls under the AIM Act phasedown: 60% of baseline in 2024–2028, 30% in 2029–2033, 20% in 2034–2035 and 15% from 2036. No refrigerant maker names a drop-in successor. In new AC equipment the low-GWP options are R-454B and R-32, which need new A2L-rated equipment.

For comparisons see R-22 vs R-407C, R-407C vs R-410A and R-22 replacement refrigerants.

Common questions

What is the glide of R-407C?

About 11°F at typical evaporating pressures (11.1°F at a 40°F dew point) and about 9°F at condensing pressures (9.0°F at a 100°F bubble point). The PT chart above gives it row by row.

Is R-407C a drop-in for R-22?

Not a true drop-in. Its pressures are close to R-22, but it needs POE oil, so an R-22 retrofit requires an oil change, liquid charging and a superheat check.