“Well I put as many as I had spaces for them but some times I had to remove an item from the outlet because the Clarifion would beep. So far I think they are trying to work, because I don't see as much dust in the air. but I have not seen dust on the walls around the Clarifions. the ones I received were out DATED, LIKE THE EXPIRED ON 12/22. SO WILL SEE HOW THINGS GO.”