Patent ID: 7533536

Claim:
A method for determining an efficiency of operation of a chiller comprising a compressor, a refrigerant, a lubricating oil adapted to lubricate the compressor, a condenser and an evaporator, the chiller removing a heat load from a process through the evaporator, comprising: (a) concurrently: (i) determining an efficiency of operation of an operating chiller; (ii) changing at least one operational parameter of the evaporator which alters an efficiency thereof, the at least one operational parameter relating to one or more of the group consisting of migration of oil to the evaporator, a buildup of non-condensable gas in the refrigerant, and moisture in the refrigerant; and (iii) changing a load on the operating chiller; and (b) predicting at least one of: a most efficient state of the operating chiller, and an efficient change in at least one operational parameter, with respect to the at least one operational parameter and with respect to the load.