HEAT UTILISATION IN AN ENVIRONMENTAL CONTROL SYSTEM

There is disclosed an environmental control system for heating at least one enclosed space. The system comprises a heat-pump circuit that includes a compressor, a heat-output stage, an expansion device and an evaporator arranged in series along a flow path for a refrigerant. The heat-output stage comprises a primary heat exchanger and a secondary heat exchanger that are both configured to transfer heat from the refrigerant to one or more external mediums in thermal communication with the at least one enclosed space. The primary heat exchanger and the secondary heat exchanger are connected in series along the flow path, such that the secondary heat exchanger will transfer excess heat energy remaining within the refrigerant after passing through the primary heat exchanger to the one or more external mediums.