Available Refrigerants, Advantages, Disadvantages and Applications
R12 or Freon 12
Properties: Refrigerant R12 or Freon 12 is said to be the most widely used of all the
refrigerants being used for different applications. The chemical name of refrigerant R12 is
dichlorodifluoromethane and its chemical formula is CCl2F2. The molecular weight of R12 is
120.9 and its boiling point is -21.6 degree F. Since R12 has the molecules of chlorine and
fluorine, it is called as chlorofluorocarbon (CFC).
Applications: R-12 is a highly versatile refrigerant that is used for wide range of
refrigeration and air conditioning applications though in many air conditioning applications it
is now replaced by R22 refrigerant. Refrigerant R12 is used in domestic refrigerators and
freezers, liquid chillers, dehumidifiers, ice makers, water coolers, water fountains and
transport refrigeration. The wide range of applications of the refrigerant are due to its safe
Advantages: 1) Safe properties: Refrigerant R12 is nontoxic, nonflammable, and non-explosive. This
makes it highly popular for the domestic as well as the commercial applications.
2) Stability: R12 is highly stable chlorofluorocarbon and it does not disintegrate even under
the extreme operating conditions. However, if it is brought in contact with the flame of fire or
the electrical heating element, it disintegrates into the toxic products. Thus whenever there is
leakage of R12 refrigerant it is advised to put all the flames off and keep the doors open so
that it can escape to the open atmosphere.
3) Suitable for wide range of operating conditions: R12 has the boiling point of -21.6
degree F (-29.8 degree C) due to which it condenses at the moderate pressures at the
atmospheric temperature. This means the discharge pressure of the compressor should be
only moderate so as to produce the condensation of the refrigerant in the condenser at the
atmospheric temperature. This helps in using the compressor of low compression ratio that
has higher efficiency. Due to this property of refrigerant R12, it is used in wide range of
applications like high-temperature, medium temperature and low-temperature applications. It
can be used will all types of compressors like reciprocating, centrifugal and rotary.
4) Miscibility with oil: Refrigerant R12 is miscible with the compressor oil under all the
operating conditions. There are two advantages of this property of R12. Firstly, there is no
problem of the oil return back to compressor. Some particles of the oil from compressor tend
to get carried away with the discharged refrigerant, because of the property of miscibility of
R12, these particles return back to the compressor easily. The second advantage of miscibility
is that the refrigerant flowing through the condenser and the evaporator is free of the oil
particles. The oil particles within the refrigerant reduce the heat transfer from it, but such
problem does not...