The type of oil used in the compressors depends on the application, the efficiency and the refrigerant. Due to the basic ingredients, the oils are divided into mineral and synthetic. Mineral oils used with CFCs and HCFCs are mainly composed of naphthalene, paraffin or mixtures of paraffin and alkylbenzene. Newer HFCs do not dissolve in mineral oil. In their case synthetic oils are used: polyvinyl polyester (PVE) polyester (PPE), polyalkylene glycol (PAG), polyester oil (POE). The most well-known refrigerant manufacturers sell their products under such brands as Fuchs RENISO TRITON, Schell CLAVUS, Mobil ARCTIC, Sunoco SUNISO, Castrol ICEMATIC, Elf ELFRIMA, ICI ELKARATE. Oil or contaminated oil can cause compressor lubrication to deteriorate or capillary clogging or even system damage. Therefore, it is important to always use the same type of oil used by the compressor manufacturer. In some systems, to prevent foaming, a crankcase heater is used to heat the oil while the compressor is stationary. There was no sudden evaporation of the liquefied medium mixed with oil.