Abstract: Disclosed is a composite branch take-off and silencer for an air distribution system wherein an air stream from an input duct may be coupled to an output duct and one or more branch ducts. The take-off and silencer includes two series-coupled sections: a static pressure regain section and a channel section adapted for coupling the input duct to the output duct and the branch ducts. The static pressure regain section outer wall and the outer path-defining wall of the associated channel section have a composite cross section characterized by a continuous curve which results in smooth changes in air flow velocity without discontinuity in either magnitude or direction thereby providing efficient conversion of velocity pressure to static pressure. These continuous curves have a direction component along their length which is increasingly directed radially from the central axis of the input duct.

Abstract: An air distribution system for a building including a mixing plenum for receiving and mixing outside and return air. An input flow concentrator and integral silencer is disposed within and coupled to the mixing plenum. The flow concentrator and integral silencer is adapted to establish a substantially axially symmetrical flow path for air from the plenum to an output port. A fan is coupled to the output port to drive the air from the output port to the main duct for distribution throughout the building.

Abstract: A static pressure regain coupler for coupling an input duct and the upstream end of a branch take-off device having a main duct and one or more channel. The static pressure regain (SPR) coupler includes an upstream end which has substantially the same cross-section as the input duct. The SPR coupler also includes a downstream end which has a first port having the same cross-section as the main duct of the take-off device, and a second port having substantially the same cross-section as the channels of the take-off device. The SPR coupler is adapted to couple most of the input airflow to the take-off main duct, and a minor portion of that air flow to the take-off channels.

Abstract: An air distribution system for a building including a mixing plenum for receiving and mixing outside and return air. An input flow concentrator and integral silencer is disposed within and coupled to the mixing plenum. The flow concentrator and integral silencer is adapted to establish a substantially axially symmetrical flow path for air from the plenum to an output port. A fan is coupled to the output port to drive the air from the output port to the main duct for distribution throughout the building.

Abstract: A damper assembly for an air passage. A damper assembly includes a disk element associated with a circular orifice of an air passage, and an actuator having an associated drive element. The disk is coupled to the drive element and a fixed reference point by a linkage so that as the actuator drive element is displaced from a first limit position to a second limit position, the disk moves between a sealing position and an open position. In the sealing position, the disk perimeter is flush against the perimeter of the orifice establishing an air-tight seal between the disk and the perimeter of the orifice. In an open position, the disk is displaced from the orifice perimeter and forms an angle with a plane defined by the orifice perimeter. An array of damper assemblies may be configured with a controller for selectively controlling the position of each actuator between the respective limit positions.

Abstract: A branch take-off and silencer apparatus for an air distribution system. The apparatus couples an input duct to one or more branch ducts and to a coaxial output duct having a similar but smaller cross-section than the input duct. Coaxial extensions of the input and output ducts define a shell region. The shell region is closed at its downstream end and open at its upstream end to oncoming air in the input duct. The shell region is divided at that upstream end by porous acoustical material into a plurality of adjacent channels which lead to a plenum near the downstream end of the shell region. The plenum is coupled to the branch ducts.

Abstract: An induction ventilation system for one or more zones. For each zone, the system includes a heat exchanger, a means for driving a heating or cooling liquid through the heat exchanger, an adjustable flow rate primary air injector and a secondary air induction inlet, and a zone temperature control. The temperature control is selectively operative to control the injector to vary the flow rate of primary air in response to sensed temperature in the zone. The temperature control is further selectively operative to maintain the flow rate of the heating or cooling liquid to be relatively constant in one form of the invention, or to vary in response to sensed temperature in the zone in another form of the invention.

Abstract: An apparatus for mixing two fluids of the same phase. The apparatus includes a mixing nozzle, an adjustable flow rate injector for introducing an annular flow of primary fluid into the mixing nozzle at a selected primary fluid flow rate, and a nozzle port adjacent to the injector for introducing an induced annular flow of secondary fluid into the mixing nozzle, wherein the secondary fluid is of the same phase as the primary fluid. In this arrangement, the ratio of the secondary fluid flow rate to the primary fluid flow rate varies inversely with the primary fluid flow rate.