Promise and potential of air-to-air energy recovery systems.

Describes and discusses the principles, advantages and disadvantages of several types of air-to-air energy recovery devices, including the open and closed run-around systems; the heat pipe exchanger; the thermal wheel and the heat exchanger. Places emphasis on the potential energy savings in heating and cooling equipment and fuel costs by recovering energy from exhaust air before it is thrown away. Results indicate annual energy savings of up to 23% with even larger savings in the size of the heating and cooling equipment. As expected greatest savings occur when large amounts of outside air are requiredfor ventilation.