Abstract: A plenum and diffuser for use with an HVAC system for distributing air through an opening in a ceiling, the plenum having a large diameter bottom opening by which air is passed through an opening in the ceiling, and having an air inlet opening. A hanger bar extends through the plenum housing over the large diameter opening. A junction box is secured to the hanger bar for supporting a light fixture or ceiling fan. A diffuser is in the form of a planar, circular structure of thin, rigid material having a circumferential outer edge and a central opening dimensioned to accommodate a junction box. The diffuser has a plurality of radially extending fins and a radially extending air slot opening in conjunction with each fin.

Abstract: A system for distributing air through an opening in a ceiling into a room, the ceiling being supported by spaced apart joists or other ceiling structural members, the air being supplied by a duct located above the ceiling, including a plenum having an open top connected to the duct and an open bottom in communication with the ceiling opening. A support bar extends through the plenum and secured at its opposed ends to ceiling structural member. A motor hanger is secured to the support bar. An air diffuser is positioned in communication with the plenum open bottom. A fan motor is supported to the lower end of the motor hanger. A plurality of generally horizontally extending fan blades are attached to and rotated by the motor. Air is passed from the duct through the plenum and diffuser into the room, distribution of the air being augmented by the fan blades as rotated by the motor.

Abstract: A system for distributing air in a room, the air being supplied by duct work. A plenum having an open top and an open bottom, the open top being in communication with the duct work. An air diffuser is positioned within the room in communication with the plenum providing passage for air flowing from the plenum into the room. A motor is supported within the diffuser having a downwardly extending motor shaft with a lower portion that extends below the diffuser. A plurality of fan blades extend horizontally from the motor shaft so that as air flows into the room through the diffuser the air is effectively distributed in the room by the action of the rotating fan blades.