Vapor compression system and method

A vapor compression system ( 10 ) including an evaporator ( 16 ), a compressor ( 12 ), and a condenser ( 14 ) interconnected in a closed-loop system. In one embodiment, a multifunctional valve ( 18 ) is configured to receive a liquefied heat transfer fluid from the condenser ( 14 ) and a hot vapor from the compressor ( 12 ). A saturated vapor line ( 28 ) connects the outlet of the evaporator ( 16 ) and is sized so as to substantially convert the heat transfer fluid exiting the multifunctional valve ( 18 ) into a saturated vapor prior to delivery to the evaporator ( 16 ). The multifunctional valve ( 18 ) regulates the flow of heat transfer fluid by monitoring the temperature of the heat transfer fluid returning to the compressor ( 12 ) through a suction line ( 30 ) coupling the evaporator ( 16 ) outlet to the compressor ( 12 ) inlet. In one preferred embodiment, a bifurcated liquid line connects the condenser ( 14 ) outlet to the first inlet of an multifunctional valve and the inlet of a metering unit.