Abstract: A variable air volume ceiling diffuser includes a damper that is raised and lowered by a linkage that is controlled by a duct temperature sensor/actuator and one or more room temperature sensors/actuators. The linkage includes a heating slide movable for the heating mode and a cooling slide movable for the cooling mode. The duct temperature sensor/actuator selects the heating slide for movement by the room temperature sensors/actuators in the heating mode and selects the cooling slide for movement by the room temperature sensors/actuators in the cooling mode. The differential movement between the heating and cooling slides moves a roller that engages a profiled cam surface attached to two lever arms. As the roller moves along the cam surface, the lever arms pivot about their axis of rotation so that the damper moves upward to close the air inlet and downward to open the air inlet.

Abstract: An airflow sensor for use in a conduit. The sensor comprises stacked first, second and third portions positioned, in use, in the conduit to define a hub and a plurality of tubes. The hub is centrally disposed in the conduit and has first and second interior chambers, a streamlined upstream-facing surface, a downstream-facing surface and a sidewall connecting said upstream and downstream facing surfaces, said sidewall having defined therein one or more static pressure ports through which the first chamber communicates with the conduit interior. The tubes extend radially from the hub, transverse to the flow. Each tube has a streamlined upstream-facing surface having defined therein one or more total pressure ports; a downstream-facing surface; and an interior passage communicating with the second chamber and communicating with the conduit interior through said total pressure ports. Each static pressure port is located downstream from a respective tube.

Abstract: A modular floor terminal mounted in the floor of an occupied space for delivering air from an underfloor air plenum to the occupied space. The modular floor terminal includes a square or rectangular housing with an air inlet at the bottom and an air outlet at the top. A rotating damper is positioned in the housing between the air inlet and the air outlet. The position of the damper is controlled by an actuator which is in turn controlled by a thermostat/controller in the occupied space above the floor.