Damper (flow)

Automatic dampers are used to regulate airflow constantly and are operated by electric or pneumatic motors, in turn controlled by a thermostat or building automation system.

Automatic or motorized dampers may also be controlled by a solenoid, and the degree of air-flow calibrated, perhaps according to signals from the thermostat going to the actuator of the damper in order to modulate the flow of air-conditioned air in order to effect climate control.

The damper may be accessible only by reaching up into the fireplace by hand or with a woodpoker, or sometimes by a lever or knob that sticks down or out.

On a wood-burning stove or similar device, it is usually a handle on the vent duct as in an air conditioning system.

In order to improve efficiency and occupant comfort, HVAC systems are commonly divided up into multiple zones.

Another style of electrically powered damper uses a spring-return mechanism and a shaded-pole synchronous motor.

However, in most applications "fail safe" indicates the damper will close upon loss of power thus preventing the spread of smoke and fire to other areas.

Highly sophisticated systems may use some form of building automation such as BACnet or LonWorks to control the zone dampers.

The damper is provided with an access door in the adjacent ductworks for the purpose of inspection and resetting in the event of closure.