Date of this Version
United States Patent No.: US 6,213,117 B1, Apr. 10, 2001
A damper unit is provided that is adapted to be positioned in a furnace duct line. The damper unit has a housing which is in communication with a fresh air source and a furnace system. The housing has a damper blade which is moveable between an open position which allows air flow through the housing and a closed position which prevents air flow through the housing. The blade is coupled with a Solenoid so that when the Solenoid is activated the blade is moved to an open position allowing air flow through the housing. Further, a fan is located in the housing adjacent the damper blade. The fan operates to move air into and out of the housing and across the damperblade when the damperblade is in its open position. In one embodiment, a pair of sealing ridges are provided on the interior of the housing. When the damper blade is in a closed position, it is in abutting relationship with the Sealing ridges So that air flow across the closed damper blade is substantially prevented by the damper blade and the sealing ridges.