This is not a straightforward question to answer. There are many factors to consider when placing an air purifier in every single room. Is the person who occupies the room allergic to air purifier? What if the air purifier is releasing stagnate, bacteria-infested air into the room? Is it really necessary to place an air purifier in every single room? It would seem absurd to put an air purifier in a room that included the kitchen, TV room, and dining area all in one place. This could be an expensive proposition to purchase an air purifier and place them in every single room.