Landis & Gyr Powers, Inc.

Steven A Bradley

Osman Ahmed

Steven L Fritsche

Steven D Jacob

Fume hood controller apparatus includes a computing means, together with associated memory, which can be configured for horizontally and/or vertically moveable sash doors by inputting the necessary dimensions of the sash doors and other structural features, such as the upper lip height, frame widths and the like. The apparatus rapidly calculates the size of the uncovered area of the fume hood as a functions of the position of the sash doors.

Method and apparatus for determining the uncovered size of an opening

A system whereby the pressure of a room containing one or more fume hoods, such as a laboratory, is to maintained at a predetermined level relative to the pressure of a reference space in the building, which may be the pressure in an adjacent corridor or an adjacent room or the like. The system involves a room controller which is part of the heating, ventilating and air conditioning apparatus of the building. The room controller is of the type which can receive electrical signals from each fume hood controller, which signals are proportional to the volume of air that is being exhausted through each fume hood. The volume indicating signals communicated from each of the fume hood controllers to the room controller enable the system to modulate the volume of air that is being supplied to the room and thereby maintain the differential pressure at the desired level with relatively quick response times.

System for controlling the differential pressure of a room having

Apparatus for controlling the air flow through a fume hood to maintain a predetermined average face velocity through an uncovered portion of an opening of a fume hood of the type which has at least one movable sash door adapted to cover the opening as the fume hood sash door is moved. The apparatus detects the position of each moveable sash door and calculates the size of the uncovered portion of the opening, measures the actual flow of air through the exhaust duct, and varies the flow of air through the exhaust duct responsive to door position signals and the actual flow signal for controlling a flow modulating means to maintain the predetermined average face velocity through the uncovered portion of the opening.

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Prairie Village, KS, United States of America

Steven A Bradley