Refrigerants
Hydrofluorocarbons (HFCs) include such refrigerants R-134a and R-23. They differ from chlorofluorocarbonsthey contain one or more hydrogen atoms and no chlorine atoms. HFCs are considered to have zero ozone depletion potential. They have only a small effect on global warming.
R-134a is typically used in new systems, specially designed for its use. Concept, that of R-134a is a simple replacement of R-12 is not correct, however. When using R-134a in retrofitting a system, many subjects should be considered (Modernization is upgrading an existing system to the new standards.) R-134a refrigerants will not easily mix with mineral oil or alkyl benzene-lubricating materials. Synthetic oils should be used for lubrication of hydrofluorocarbons; existing oil should be replaced.
Use of proper recovery device is necessary for the removal of R-12. There are also a number of other factors that must be considered. They include the performance of the system, replacement of equipment and existing materials and lubricant compatibility. Before retrofitting a system, the technician should always check with the manufacturer to be sure that he will be correct.
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Refrigerants