| abstract |
A lubricant/working fluid composition for use in mechanical vapor compression type heat transfer devices is described wherein the working fluid is preferably tetrafluoroethane and the lubricant is an ester which is miscible with the working fluid at 10% over a temperature range of -50° C. to +80° C. and has a viscosity of 5 to 100 cSt at 40° C. Useful esters include pentaerythritol partial ester of straight chain C 5 or branched chain C 7 carboxylic acids. The esters are compatible with non-chlorine containing working fluids and exhibit a low level of corrosion. |