Overview VENCO Fan Type Air Dampers are used together with the axial smoke exhaust fans. If one of the axial smoke exhaust fans installed side by side stops working, the fan type air damper prevents short circuit of the exhaust air. Also, they are used as motorized back draft damper. They can be installed at the air inlet or air outlet of the Axial Smoke Exhaust Fans. The damper blades are designed to create minimum pressure drop while they are open and allow minimum air leakage while they are closed. The damper casing and blades are made up of galvanized steel sheet and the blades are controlled by an On/Off servomotor.