HEAVENLY AIR eliminates all these problems in one stroke! The ionization chamber is fitted into the air register (vent) cover plate where the forced air exits into the room. HEAVENLY AIR is fitted with a pressure switch. When forced air starts coming, its pressure turns on the ionization grid, which cleans all the incoming air. This means the WHOLE ROOM IS CLEAN! No more "Clean Air Island". It does not have any fans or mechanical filters, therefore no extra noise.