R-407C

R-407C is a mixture of hydrofluorocarbons used as a refrigerant. It is a zeotropic blend of difluoromethane (R-32), pentafluoroethane (R-125), and 1,1,1,2-tetrafluoroethane (R-134a). Difluoromethane serves to provide the heat capacity, pentafluoroethane decreases flammability, tetrafluoroethane reduces pressure.^[1] R-407C cylinders are colored burnt orange.

R-407c container

This refrigerant is intended as a replacement for R-22 in existing refrigerators.^[2] R-22 production will be phased out by 2020 as per the Montreal Protocol as the chlorine in R-22 can lead to ozone depletion.^[3] As the components in R-407C lack chlorine it does not contribute significantly to ozone depletion in the stratosphere. Despite improved environmental impact with respect to ozone depletion, R-407C still has a calculated 100-year global warming potential of 1774,^[4] only slightly lower than calculated value of 1960 for the R-22 refrigerant it replaces.^[5] The use of R-407C and other high GWP hydrofluorocarbon refrigerants is being phased out worldwide in accordance with the Kigali Amendment to the Montreal Protocol. Its use was barred for many applications in the United States on 1 January 2025 with near-complete phaseout planned by 1 January 2028.^[6]

Physical properties

Physical properties of R407C refrigerant

Property	Value
Formula	CH2F2 R32 (23%) CF3CHF2 R125 (25%) CF3CH2F R134a (52%)
Boiling point (°C)	−43.8
Saturated liquid density (25°C), kg/m3	1138
Saturated vapour density (25°C), kg/m3	43.8
Critical temperature (°C)	86.4
Critical pressure, bar	46.3
Liquid heat capacity @ 25°C, (kJ/(kg·K))	1.533
Vapour heat capacity @ 1.013 bar (kJ/(kg·K))	1.107