Patent ID: 6938438

Claim:
A vapor compression system, comprising: a main circuit comprising a compressor, a condenser, an expansion device and an evaporator serially connected by main refrigerant lines, said compressor having a suction port, a discharge port and an intermediate pressure port; an economizer circuit comprising an auxiliary expansion device and economizer refrigerant lines connected between said condenser and at least one of said intermediate pressure port and said suction port of said compressor; a bypass circuit comprising bypass refrigerant lines connected between said intermediate pressure port and said suction port; and a heat exchanger adapted to receive a first flow from said main refrigerant lines and a second flow selectively from said economizer circuit and said bypass circuit, said first flow and said second flow being positioned for heat transfer relationship within said heat exchanger, wherein said system is selectively operable in a first mode wherein said economizer circuit is active and flows through said heat exchanger and said bypass circuit is inactive, and a second mode wherein said bypass circuit is active and flows through said heat exchanger and said economizer circuit is inactive, and wherein said heat exchanger is active for cooling said first flow in both said first mode and said second mode.