Marine R407c Refrigerant is a zeotropic blend of R32, R125, and R134a with a composition of 23%/25%/52% by weight. It has a boiling point of -43.8°C (-46.8°F) at atmospheric pressure and a critical temperature of 86.1°C (187°F). The refrigerant operates within a pressure range of 1.2 MPa to 3.2 MPa (174 psi to 464 psi) depending on temperature conditions.
R407c has a density of approximately 1.15 kg/m³ in gaseous form and 1,140 kg/m³ in liquid form at 25°C (77°F). Its viscosity ranges from 0.012 mPa·s (gas) to 0.2 mPa·s (liquid) at standard conditions. The buoyancy of R407c vapor is slightly higher than air due to its molecular weight of 86.2 g/mol.
Marine refrigeration systems using R407c typically employ copper or stainless steel tubing with diameters ranging from 6 mm to 22 mm (1/4" to 7/8"). The refrigerant is compatible with POE (polyolester) lubricants and requires hermetic or semi-hermetic compressors. System capacities vary from 1 kW to 100 kW (0.28 TR to 28.4 TR) depending on application.
R407c is classified as an A1/A1 safety group refrigerant (non-flammable, low toxicity) with a GWP of 1,774. It has a volumetric cooling capacity approximately 95% that of R22. The refrigerant is typically supplied in 11.3 kg (25 lb) or 680 kg (1,500 lb) cylinders, meeting AHRI Standard 700 purity requirements.
