Refrigerant Solutions - the refrigerant specialists

Low global warming & higher efficiency replacement for R404A

RS-50 has a Global Warming Potential (GWP) of less than one half of R404A together with a higher efficiency which delivers energy savings and a lower contribution to global warming.

RS-50 can be used to replace R404A in both new & existing equipment. Mass flow of RS-50 is lower than R404A so that reducing the opening of the expansion device may be required. No changes to other hardware are necessary. A significant increase in energy efficiency compared to R404A and R507 can be expected. Users will achieve a lower carbon footprint due to the lower direct GWP of the refrigerant & its inherent higher efficiency.

Replacement for R22 in refrigeration applications

RS-50 is a non ozone depleting and non flammable replacement for R22 in medium and low temperature refrigeration applications. The efficiency and cooling capacity of RS-50 provide a close match for R22 in overall system performance. Flow rate is identical to R22 which avoids the need to change or alter existing pipework.

Performance Characteristics

  • Global Warming Potential less than half of R404A & R507
  • Suitable in OEM & retrofit applications
  • ASHRAE safety classification of A1
  • Higher Coefficient of Performance than R404A & R507
  • Higher capacity than R404A, R507 & R22
  • Effective at medium and low temperatures
  • Good match for R22 in refrigeration applications
  • Mass flow equivalent to R22 and considerably lower than R404A & R507
  • Zero Ozone Depletion Potential
  • Non flammable & low toxicity
Global Warming Potentials
Global Warming Potentials


Because the properties of RS-50 are similar to R404A & R507, it is suitable for use in many of the applications where R404A & R507 are commonly found including supermarket display cases, cold stores, freezers, refrigerated transport, ice machines, cold storage, transportation of foodstuffs, freezer cabinets, beer cellars, freeze dryers & environmental test chambers.

R22 is also used in many of these refrigeration applications where RS-50 can be a suitable replacement.

Refrigerant Capacities
Refrigerant Capacities


RS-50 is compatible with the same (POE) lubricants which are commonly used with R404A & R507 so that there is no need to change the oil when converting from R404A & R507 to RS-50. When replacing R22 with RS-50, the lubricant should be changed to a polyol ester oil.


RS-50 is non flammable under all conditions of fractionation as per ASHRAE Standard 34. The components of RS-50 have been subjected to toxicity tests carried out by Alternative Fluorocarbons Environmental Acceptability Study (AFEAS), and have been declared to be of low toxicity. RS-50 has been designated a refrigerant number of R442A by the ASHRAE with a safety classification of A1.

Mass Flow Rates
Mass Flow Rates


Because RS-50 is a blend, it should be charged into the system in the liquid as opposed to vapour form. There is no need to make hardware changes when converting from R404A & R507 to RS-50 other than reducing the opening of the expansion device. Because RS-50 has a similar flow rate to R22, there is not need to adjust or change the expansion device during a retrofit.

Pressure Enthalpy Chart
Pressure Enthalpy Chart

Physical Properties

Property   RS-50 R404A R22
Molecular weight   81.8 97.6 86.5
Boiling point (1 atm) °C -46.5(1) -46.2(1) -40.8(1)
°F -51.61(1) -51.21(1) -41.5(1)
Temperature Glide K 4.6 0.5 0
Critical Temperature °C 82.4 72.1 96.1
°F 180.3 161.7 205.1
Critical Pressure bara 47.6 37.3 49.9
psia 690 541 724
Liquid Density (25°C) kg/m3 1108 1044 1191
Density of saturated vapour (25°C) kg/m3 47.7 65.3 44.2
Latent Heat of Vaporisation at boiling point kJ/kg 266(1) 200(1) 234
Cv (25°C & 1bara) kJ/kg.K 0.727 0.784 0.559
Cp (25°C & 1bara) kJ/kg.K 0.838 0.877 0.662
Cp/Cv (25°C & 1 bara)   1.152 1.118 1.185
Vapour Pressure (25°C) bara 13.3(1) 12.6(1) 10.4
psia 192(1) 182(1) 151
Vapour Viscosity (25°C & 1 bara) cP 0.0126 0.0120 0.0126
Liquid Viscosity (25°C) cP 0.141 0.128 0.164
Liquid Thermal Conductivity (25°C) W/m.K 0.0857 0.0636 0.0835
Surface Tension (25°C) N/m 0.00661 0.00455 0.00808
Specific heat of liquid (25°C) kJ/kg.K 1.58 1.54 1.26
Ozone Depletion Potential ODP 0 0 0.055
Flammability limit in air (1 atm) vol% none none none
Inhalation exposure (8 hour day & 40 hour week) ppm 1000 1000 1000

(1) Bubble point