The SVAD-RR diffuser is a 24in / 600mm round ceiling VAV diffuser with built-in electric motor and DDC controller, temperature sensors provide VAV cooling and VAV heating. The disc damper moves open and close to control air flow (warm or cool) into the room in response to room temperature. The damper is modulated by a motor. Room air is postively induced over the built-in temperature sensor, or sensed at the wall mounted thermostat / external temp sensor / desktop remote built in temp sensor for an accurate measurement of room temperature in both cooling and heating.