Manual for Refrigeration Servicing Technicians - UNEP - Division of ...

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Refrigerants
Synthetic refrigerants
Refrigerators from the late 1800s until 1929 used the higher
toxicity gases - ammonia, methyl chloride, and sulphur dioxide - as
refrigerants. Several fatal accidents occurred in the 1920s because
of methyl chloride leakage from refrigerators. A collaborative effort
began between three American corporations to search for a less
dangerous method of refrigeration.
In 1928, CFCs and HCFCs were invented as substitutes for the
higher toxicity and flammable refrigerants. CFCs and HCFCs
are a group of aliphatic organic compounds containing the
elements carbon and fluorine, and, in many cases, other halogens
(especially chlorine) and hydrogen. Most CFCs and HCFCs
tend to be colourless, odourless, non-flammable, non-corrosive
substances. Because CFCs and HCFCs have low toxicity, their
use eliminated the danger posed by refrigerator leaks. In just
a few years, compressor refrigerators using CFCs became the
standard for almost all home kitchens. In subsequent years, they
were introduced in a series of products, including R11, R113,
R114 and R22, that helped the expansion of the RAC industry
and applications. With the advent of the Montreal Protocol, HFC
refrigerants were developed during the 1980s and 1990s as
alternative refrigerants to CFCs and HCFCs.
Three groups could be considered:
Those with ozone depleting potential 4
Those without ozone depleting potential 4
Heat transfer fluids 4
More about the classification and use of different refrigerants:
Using Refrigerant Blends – issues and concepts 4
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