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.

For obtaining a noiseless or substantially noiseless process of a flow passing through a throttle or damper device, the flow is given a speed increase with increasing acceleration in the direction of flow. Further, at least a substantial part of the dynamic component of the energy state of the flow is quenched within or immediately after the device by means of a counter-directed flow having a similar dynamic component. The invention also concerns a throttle or damper device for such a noiseless or substantially noiseless process of a flow.

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.

A system for the economic and efficient ventilating, cooling and heating of an enclosed space, such as a room or rooms within a building, through controlled ventilation of room air between an upper hotter building portion and a lower cooler building portion with the portions constituting different temperature zones in the building. The system includes a reversible ceiling fan facility and motorized inlets in the lower building portion and motorized outlets in the upper building portion, the inlets and motorized outlets being formed in the building and communicating with the exterior thereof. Air conditioning facilities are mounted within the building and include specifically an inlet for air to be cooled in the lower cooler building portion and another inlet for air which is above the inlet for the air to be cooled and which is for drawing air from the upper hotter building portion down for use as a heat sink for the condenser of the air conditioning facility and wherein the air conditioning facility includes a cold air discharge specifically disposed in the lower building portions and another exhaust above the lower cooler building portion for exhausting the sink air which had been drawn down from the upper hotter building portion.

A system and method of vent placement within a building is provided for improved passive ventilation. Vents are provided within the dividing structures or material layers that form the building's exterior and interior walls, ceiling, roof, floor, and/or intermediate story-defining "ceiling-floors." Preferably, each vent is not a conventional ventilation stack and is oriented generally along a planar portion of the dividing structure within which the vent is positioned. Preferably, each vent is substantially entirely contained within its associated dividing structure. Vents are provided in corner sections of exterior walls, roof-portions, and the bottom floor of the building. Vents are also provided in corner sections of the ceiling portions, floor portions, and wall portions that define the interior rooms of the building. The vents are preferably vertically aligned throughout a substantial portion of the height (or more preferably substantially the entire height) of the building, at one or more horizontal positions thereof, to thereby produce one or more substantially vertical flows of air upward and out of the building, without the use of stack vents.