Heat extraction or reclamation apparatus

A heat extraction or reclamation system particularly adapted to recover otherwise rejected heat from the refrigerant gas flowing through air conditioning and refrigerating systems includes a counter-flow heat exchanger for transferring heat to a medium such as water, the heat exchanger being installed in the tubing upstream of the conventional condenser. The heat extraction system has a pump for circulating water or other medium to be heated, located on one side of the heat exchanger. Hot refrigerant gas, the so-called superheated gas flowing from the compressor of the air conditioning or refrigerating system, is circulated through the other side of the heat exchanger. The pump flow rate and the heat transfer area between the refrigerant gas and the water or other medium are chosen to ensure that the refrigerant gas outlet quality remains within limits which ensure flow continuity in operation. Refrigerant gas leaving the system will contain some liquid in the form of droplets or a small stream. The water temperature is maintained within limits by stopping the pump when the inlet water temperature reaches a predetermined maximum value. Refrigerant velocity through the heat exchanger is reduced compared to velocity at compressor discharge in some embodiments to lengthen residence time in the heat exchanger sufficiently to increase heat transfer from the refrigerant gas and yet provide an excess quantity of heat in the refrigerant gas compared to the heat removal capacity of the flowing water.