US Patent 7698903 Energy efficient ventilation system

The energy efficient ventilation system provides tempered air to an air to air heat exchanger, such as a heat pump. The system includes independent air intake sources from a tunnel, a structure, and the exterior of the structure that direct air to a control module. Regulators control the amount of air that enters the control module from the air intake sources. The control module mixes the intake air and distributes the tempered air to the structure and to the air to air heat exchanger.