Replacement for R12 Refrigerant

Refrigerant R12 or Freon 12 is the most widely used of all the refrigerants for different refrigeration and air conditioning applications. R12 is a highly versatile refrigerant that can be used in wide range of the operating conditions without getting disintegrated. The whole field of the refrigeration has become much easier and useful mainly because of R12 refrigerant.

Unfortunately, R12 is a chlorofluorocarbon (CFC) with the chemical formula CCl₂F₂. It has unusually high potential to cause the depletion of the ozone layer in the upper layers of the atmosphere that causes the greenhouse effect. Due to this, as per the Montreal Protocol, R12 has to be phased out completely by the year 2021. It is very difficult to find alternative replacements for such a widely used refrigerant, however, a few of the viable replacements to R12 have been found.

The best replacement for R12 is considered to be R-134a. The chemical name of R134a is tetrafluoroethane and it chemical formula is CF₃CH₂F. It is a hydrofluorocarbon (HFC) and has zero ozone depletion causing potential and very low greenhouse effect. R-134a is nonflammable and non-explosive and has good chemical stability though it has some affinity towards moisture.

The other two refrigerants that are considered good replacements for R12 are R-401a and R-401b. R-401A is the mixture by weight of 53% of R-22, 13% R-152a and 34% R-124. It is good replacement for R12 in the applications where the evaporator temperature is -23 degree C and above. It can be used applications like walk-in coolers, food and dairy display cases, domestic refrigerators, and beverage dispensers and vending machines.

R-401b is the mixture by weight of 61% R22, 11% R-152a and 28% of R-124. This refrigerant is suitable for domestic and commercial freezers and transport refrigeration.

Among all the alternatives available for R12, R-134a is considered to be the best available option because it has favorable toxicity data and good chemical stability. This refrigerant has been tested by the chemical industry’s Program for Alternative Fluorocarbon Toxicity Testing (PAFTT) and the results indicate that if does not pose the hazards of cancer and birth defects.

R-134a is nonflammable and non-explosive, however its mixture with air is found to be combustible at high pressures and they can cause injury or property damage. R-134a is non-corrosive with the copper, aluminum and standard steel materials. R-134a is the single component refrigerant and not the blend like the other alternatives. While handling R-134a, the technicians should work in the ventilated place and should avoid inhaling the gas.