Lubrication of refrigerating compressors (reciprocating and screw) using ammonia as a refrigerant.PAO (polyalphaolefin) base oils to improve oil drain interval and ensure good performances even at very low temperature.Field of application : evaporator temperature down to -50°C.Advantages:High resistance to oxidation in the presence of ammonia. Base oils and additivation system specillay selected to avoid the formation of black sludges (reaction between oil and ammonia). Low pour point, eliminating the risk of any residual lubricant freezing in the evaporator, there by providing excellent heat exchange. Very high flash point given the low volatility of LUNARIA NH oils : oil consumption is reduced by 30 to 50 % compared with conventional oils. Good compatibility with common elastomers (chloroprene, NBR….).