Motorized Fresh Air Intake Dampers
A damper is any device that will restrict, regulate or alter the flow of a substance. In the case of HVAC products the damper will change the flow of air. Dampers can come in any size and shape from the 3” round found in bathroom exhaust fans to and unlimited size. The largest we have installed at Signature Air measured approximately 15 feet long by 6 feet high. Motorized dampers open and close with the operation of an electric or pneumatic motor that is connected via linkage arms to the individual blades of the damper. There are many methods of signaling the damper to open or close and in most cases the dampers will be inter connected (interlocked) with other devices such as an exhaust fan or a make-up air fan. Dampers of this type are used in places or on occasions where the transfer of air flow is not required at all times. Different municipalities require motorized dampers in the hallway pressurization outlets of Condominiums. In this case the damper is powered open at all times and should a fire or power interruptions occur the dampers will automatically close under spring tension. These dampers can also be controlled by the fire department at the lobby entrance to control the spread of fire or smoke.
Most motorized dampers are constructed out of extruded aluminum to reduce the weight and power requirements of the motor actuator and can come in a variety of styles depending upon the quality of air seal required. In many cases a motorized damper section is centered between a screen mesh on one side and angled louvers on the other side. The screen mesh will keep birds, rodents or hands from using the damper as a passageway. The louvers will prevent rain from entering the building and make the opening more aesthetically pleasing on the outside of the structure.
Another example of where these dampers are used is in this same section under parking garage exhaust systems.