Patent attributes
A thermally powered VAV diffuser assembly (21, 221) having a housing (42, 242) formed for coupling to a supply air duct or conduit (22, 222), a damper (24, 224) mounted across a supply air opening (27, 227) for movement relative thereto to vary the volume of supply air discharge from the diffuser and a thermally powered damper position controlled device or assembly (28, 228). The control assembly (28, 228) includes not more than two sensor-actuators (31, 32, 231, 232) and a movable linkage assembly. The linkage assembly transmits movement of the sensor-actuators (31, 32, 231, 232) to the damper (24, 224) for displacement of the damper (24, 224) to vary the volume discharged and to produce change-overs between heating and cooling modes. The heating mode and cooling mode set point temperatures are each independently adjustable, and the movable linkage assembly includes a lever (33, 233) pivoted about two pivot points by axles (82, 83, 282, 283) which slide in slots (87, 88, 287, 288). The sensor-actuators (31, 32, 231, 232) and all of the movable linkage assembly are located on a room side of the movable damper (24, 224) so that removal of the appearance panel (34, 234) exposes these elements for ease of maintenance, repair and replacement. An adjustable minimum flow stop (233a, 233b, 233c) balancing arm (220) and change-over linkage (275) also are provided.
