An air-pressure-control system (110), the system comprising a system inlet,a system outlet, and a variable-speed fan (130) configured to operate at a speed.A motor controller in communication with the fan is configured to control thespeed of the fan. A differential- pressure transducer (150) configured to monitoran air pressure at the system inlet and an air pressure at the system outlet. A closed-looppressure controller in communication with the motor controller and differential-pressuretransducer (150), wherein the pressure controller is configured to vary thespeed of the fan (130) based on the pressure differential between the inlet andoutlet of the system, thereby controlling a pressure within a space. An ultravioletkill chamber (140) may be disposed between the inlet and outlet to expose airborneparticulate to UV radiation. The system may also have a filter located withinan air-flow path between the system inlet and system outlet.
