AN-92-05-2 — High-Viscosity Ester Lubricants for Alternative Refrigerants

With more polar refrigerants such as HFC134a (a replacement for CFC12), one problem is developing a miscible oil. Proper selection of a synthetic lubricant may improve compressor durability or performance. Describes the development of high-viscosity esters (ISO 68 and above) and their interaction with refrigerants. Data on the chemical and physical properties of these lubricants are reported with HFC134a and other selected alternative refrigerants. Stability and lubricity test results are provided for durability considerations. Viscosity of oil-refrigerant solutions with an ISO 68 modified ester and HFC134a are presented to help evaluate the lubricant for hydrodynamic lubrication and sealing of compression areas.

KEYWORDS: viscosity, lubricants, refrigerants, R134a, R12, compressors, durability, performance, properties, testing, hydrodynamics, refrigeration, air conditioning, compatibility