The use of HFC refrigerants and Polyester [POE] lubricants for air-conditioning and refrigeration have generated new system chemistry related problems. New and redesigned system protectors have been developed to counteract these problems and provide a long, reliable life for the operating refrigeration system.
Moisture is the major problem causing contaminate for HFC/POE oil systems just as was for CFC and HCFC systems using Mineral oil. Many HFC's can hold much more water than their CFC counterparts but the oil differences are much worse than those of the refrigerant. POE oil can hold as much as 10 times more water than Mineral oils. In addition, evacuation has proven ineffective at removing this moisture so as a filter-drier is required to perform this function.
Water poses a new problem for POE oils above and beyond those experienced with Mineral oil. POE oil will react with water to form organic acids at normal operating conditions in refrigerating and air-conditioning systems. This reaction starts at water levels as low as 75ppm. These acids attack system components including motor insulation and metallic components --- reducing system life.