#$%^&*AU2014203203A120140703.pdf#####ABSTRACT: An air-pressure control system, the system comprising: a system inlet； 5 a system outlet； a first filter located within an airflow path between the system inlet and system outlet. a variable-speed fan configured to operate at a speed； 10 a motor controller in communication with the fan and configured to control the speed of the fan； a differential-air-pressure transducer configured to monitor an air pressure differential between the system inlet and the system outlet； and 15 a closed-loop controller in communication with the motor controller and the differential-pressure transducer, wherein the pressure controller is configured to vary the speed of the fan based on the pressure differential between the inlet and outlet of the system, thereby 20 controlling a pressure within a space. 54781911 (GHMatters) P79549.AU.2 12/06/20141/12 100 180 120-150 170160 110 Clean Air FIG.1I
