An evaporator for evaporating a phase change refrigerant in a space conditioning system, such as an air conditioner, heat pump or refrigeration system, is provided. The evaporator includes an inlet for introducing the refrigerant into the evaporator, an outlet for discharging the refrigerant from the evaporator and plural conduits defining a plurality of hydraulic flow paths between the inlet and the outlet. In accordance with the invention, a separator is provided to substantially separate liquid refrigerant from vapor refrigerant before the refrigerant is introduced into the evaporator to enhance refrigerant distribution within the evaporator, thereby improving evaporator performance.