Patent ID: 6595429
Filing Date: 2003-07-22
Classification: F24F,F25D

Abstract:
An apparatus for forming an air stream across a doorway between areas of relatively cool and warm air masses including a supply air plenum with an outlet aperture at a first side of the doorway, a return air duct with an inlet aperture at a second side of the doorway and an intermediate air duct extending between the supply plenum and return air duct, the apparatus comprising:an air mover for moving an air stream across the doorway into the inlet aperture to the return air duct through the intermediate air duct to the supply air plenum and out of the outlet aperture; a heater in thermal communication with the air stream for warming the air stream; an electronic control unit controlling the operation of the heater; a first air sensor located in one of the relatively cool and warm air areas providing an air characteristic input to the control unit; and a second air sensor located in contact with the air stream providing an air stream characteristic input to the control unit; wherein the control unit continuously monitors the air characteristic input and the air stream characteristic input and operates the heater to maintain the temperature of the air stream at a point substantially along a line representing the mixing of the air stream with one or both of the air masses that is tangent to the psychrometric saturation curve.