Central vacuum cleaner control, unit and system with contaminant sensor

A central vacuum cleaning system has a central vacuum unit with a motor , a motor compartment , and a vacuum chamber . The system also has a control circuit for controlling power to the motor , and one or more airborne contaminant sensors for sensing contaminants within the system . The sensors may be located in pipes motor compartment , vacuum chamber and hose handle . Vacuum air may be drawn through aperture in wall valve