Patent ID: 8096862

Claim:
An isolation damper comprising: a housing having an interior chamber, an inlet and an outlet, a primary damper mounted in said housing proximate said inlet, movable between an open position and a closed position, a secondary damper mounted in said housing proximate said outlet and spaced apart from said primary damper, movable between an open position and a closed position, said primary damper and said secondary damper dividing said interior chamber of said housing into first, second and third chambers, wherein said first chamber extends between said inlet and said primary damper, said second chamber extends between said primary damper and said secondary damper and said third chamber extends between said secondary damper and said outlet, and a blower having an inlet in communication with said third chamber and an outlet in communication with said second chamber, said blower being energized to blow air into said second chamber only when said secondary damper is in said closed position.