Indoor air pollution can be reduced three ways. The greatest thing to do is remove all sources of pollutant emissions. The next best thing is to increase ventilation in the home. The third, and least effective method, is to clean the air. While air cleaning may be useful when used together with the first two methods described, by itself air cleaning will probably not be adequate.
Some air cleaners may be effective in reducing the health effects of small suspended particles in the air, like dust or spray mists. Some air cleaners are also effective in removing invisible particles like tobacco smoke. This may reduce the health risks associated with environmental tobacco smoke (secondhand smoke).
Although some air cleaner manufacturers claim that their products can reduce allergic reactions caused by pollen, molds and animal dander, the truth is that most of these particles are not found in the air, but rather have settled on household surfaces.
Air cleaners that claim to remove gaseous pollutants must contain special media like activated carbon or alumina.
Several types of air cleaners are accessable. Some are mechanical filters like the typical furnace filter. Electronic air cleaners trap use an electrical field to trap charged particles. Ion generators spray charged ions into the air which then charge the particles already there. The charged particles are then attracted to the room's surfaces or to a charged collector. Finally, there are hybrid devices that employ two or more of the above methods.
To determine if an air cleaner will perform adequately in your home, rate air cleaners according to efficiency (the percentage of particles removed), their capacity (how much air can be handled by the device), the volume of air you wish to clean, and the importance of periodic air cleaner maintenance.
If you decide to purchase an air cleaner, install it and maintain it according to the manufacturer's directions. Install it near a specific pollutant source if you have one. Make sure cleaned air is directed into occupied spaces. Ensure that air inlets and outlets are not blocked.