A synthetic ester lubricant used with most HFC and HFO refrigerants.
Polyolester oil is miscible with HFC refrigerants, where mineral oil is not. It is also hygroscopic: it absorbs moisture from the air quickly, and moisture in POE can form acids. Keep containers sealed, limit the time a system is open, and use the oil the compressor manufacturer specifies.
Exam work areas
C · Planning installs and retrofits D · Installing systems and controls