DUCT PRESSURE POWERED AIR VOLUME CONTROLLER

摘要

The controller is connected to a duct pressure powered air terminal unit. A pressure drop is sensed in the terminal unit and to a specific air flow in the unit. The sensed pressure drop is communciated to the controller as two pressure signals. The controller bleeds one pressure signal to control the inflation of a bag or bellows and to modulate the terminal unit to maintain a constant volume air flow through the unit as duct static pressure varies. The controller bleeds the second pressure signal to maintain at least a minimum flow through the unit.