With the ban of the of refrigerant R- 22 (chlorine-based refrigerants) and phasing in new hydrofluorocarbon (HFC) refrigerants, the need of new lubricating oil for the compressor has also cropped up. These lubricants must be reliable and efficient as the mineral oil used with old refrigerants. The synthetic polyolester (POE) oils meet this requirement and are used with all R-410A systems. They belong to the family of synthetic lubricants. They are completely wax-free unlike mineral oils. They also offer better thermal stability, and are more compatible in HFC refrigerants than mineral oils.