Abstract: A variable volumetric flow heat exchanger for a building air-to-air heat recovery system that is operable at a high volumetric flow rate and at a low volumetric flow rate. The heat exchanger includes multiple heat exchange banks, including at least one continuous duty heat exchange bank, and at least one cyclic heat exchange bank. A damper assembly includes at least one damper module having at least one damper reciprocative between open and closed positions. A control system moves the heat exchanger damper to the closed position when the heat recovery system is operated at the low volumetric flow rate and moves the heat exchanger damper to the open position when the heat recovery system is operated at the high volumetric flow rate.

Abstract: An air-to-air heat recovery system for use with a building ventilation system includes first and second heat exchange banks and at least one damper module. Each damper module includes a damper disposed within a substantially rectangular housing having first, second, third, and fourth ports. The first port is connected to the ventilation system exhaust line, the second port is connected to the ventilation system supply line, the third and fourth ports are connected to the first ends of the first and second heat exchange banks, respectively. The damper is periodically reciprocated between first and second positions, directing air flow between the first port and the third port and between the second port and the fourth port in the first position, and directing air flow between the first port and the fourth port and between the second port and the third port in the second position.

Abstract: An air-to-air heat recovery system for use with a building ventilation system includes first and second heat exchange banks and at least one damper module. Each damper module includes a damper disposed within a substantially rectangular housing having first, second, third, and fourth ports. The first port is connected to the ventilation system exhaust line, the second port is connected to the ventilation system supply line, the third and fourth ports are connected to the first ends of the first and second heat exchange banks, respectively. The damper is periodically reciprocated between first and second positions, directing air flow between the first port and the third port and between the second port and the fourth port in the first position, and directing air flow between the first port and the fourth port and between the second port and the third port in the second position.