February 26, 2012 at 3:03 PM EST - Updated June 26 at 4:05 PM
HVAC (Heating, Venting and Air Conditioning) System Dampers A damper is an adjustable plate for controlling the draft in an HVAC System. Dampers open and close based on the portion of the HVAC system in use, and they control air flow and venting of the system. Depending upon how elaborate the HVAC system is, there can be multiple zone dampers, each individually linked to a zone-specific thermostat, which in turn connects back to the master thermostat so that the temperature in each zone can be managed separately.
Damper Mechanism The damper mechanism is almost always made of lightweight metal that is impervious to heat and cold. In most modern HVAC systems, the damper mechanism is automatic, operated by a small motor, and its movements directed by a thermostatic controller.
Room Dampers At the end of each branch of HVAC piping is a terminus vented grate. These grates typically have a lever control that can be moved up and down or left to right to open, close or redirect air flow coming through the louvers. This is a comfort control feature in rooms to prevent, for example, the cool air of an air conditioner blowing directly on someone as they lay in bed. They also serve as a system-wide air flow management control, directing cool or warm air into parts of the home most requiring it and skipping those rooms or areas that do not. An example of this would be western facing rooms, which are heavily covered in windows coping with afternoon sun, as opposed to the eastern side of a home shaded by overhead trees. Irrespective of where in the house the thermostat is placed, the room damper system can aid in efficient energy management in both heating and cooling modes.