Abstract: A complete system for indoor air pollution control and its components is disclosed herein, incorporating a furnace, heat pump or the like for supplying conditioned air to a room or zone via a duct network. Air filters are removably disposed at exhaust vents leading into the room or zone and intake vents are included for drawing air away from the room or zone for re-circulation. Ambient air intake vents are included in the duct network and the network is suitable for multiple level buildings. The system further includes sensing circuits within the duct work or zone which tests or senses the air for multiple characteristics of air quality and a panel having a variety of displays portrays the results of the individual characteristics being monitored. Such characteristics of air quality include ozone, carbon monoxide, nitrogen dioxide, etc.