An environmental control system includes a primary heat exchanger operable to transfer heat from an air source to a refrigerant in a generator flow and output an air flow. An ejector is operable to produce an intermediate refrigerant flow based on receiving the generator flow as a motive fluid and drawing a vapor refrigerant flow as a suction fluid. A refrigerant condenser is operable to convert the intermediate refrigerant flow to a liquid refrigerant flow. A pump is operable to provide the refrigerant to the primary heat exchanger from a portion of the liquid refrigerant flow. An expansion device is operable to expand the liquid refrigerant flow prior to entering an evaporator. The evaporator is operable to convert the liquid refrigerant flow to the vapor refrigerant flow and produce a cooled evaporator air flow output based on the air flow.