Purpose of an in-line damper
In-line ventilation dampers are used to release and restrict the flow of air from zone to zone. Much like a dam in a river, it can permit or block hot or cold air from the furnace or boiler to different zones of a building. In-line dampers block the flow of air, increasing the amount of hot or cold air to other parts of the building. Sophisticated buildings have HVAC (Heating, Ventilation, Air Conditioning) systems that use mechanized dampers to open and close air flows to parts of buildings or homes. Regular residential properties may have corrugated vent pipes controlled by a wing nut and metal plate.
Electric in-line dampers
A mechanical in-line damper is managed by a high-end thermostat or a computer-controlled HVAC system. Depending on the program for heating, the system will open or close dampers. This is most evident in office buildings when staffers go home for the day. Climate control systems will typically shut the dampers to areas that go unoccupied. The dampers will reopen at a predetermined time to reheat the building for incoming staff.
Conventional in-line dampers
Regular in-line dampers are controlled by a flat metal plate. The plate is clipped to a screw which pokes through the pipe and is controlled by a nut. The nut opens and closes the pipe, permitting the flow of air. Because a user needs access to exposed pipe, these dampers are typically seen in basements, where a user can manage airflow to other parts of a house.