Patent ID: 6033302
Filing Date: 2000-03-07
Classification: F24F,G05B

Abstract:
A controller for controlling the air pressure within a room in a building having at least one space adjacent to the room, the building having a heating, ventilating and air conditioning (HVAC) system with a supply duct adapted to supply air to the room and an exhaust duct adapted to exhaust air from the room, the system having a component for controlling the supply air flow into the room, the room having at least one additional exhaust independent of the HVAC system, said apparatus comprising:a feedforward means for generating a feedforward control signal based on desired flow set points in the supply duct and general exhaust duct and based on identifying characteristics of the component, said component comprises a supply damper/actuator and an exhaust damper/actuator, the characteristics comprising the flow rate of air entering the room, the set point of the flow rate of air entering the room, the flow rate of exhaust air leaving the room, the set point of the flow rate of the exhaust air leaving the room, the authority of the supply damper/actuator, the authority of the general exhaust damper/actuator and calculated system variables;a feedback means for generating a feedback control signal based on measured system variables; andmeans for combining the feedforward control signal and the feedback control signal to achieve control of the local component.