Many people believe that an air cleaner will help their family be healthier.  Using an air cleaner or air purifier in your home supposedly helps reduce dust, pollen and other respiratory irritants.  There are three types of air cleaners,  High Efficiency Particulate Air (HEPA) filters, electrostatic precipitators, and ozone generators.

From the Arizona Daily Star:

1. High Efficiency Particulate Air (HEPA) filters: Consumer Reports says air cleaners with these filters are among the best performers. But homeowners can more easily improve their indoor air with other methods, such as banning indoor smoking, keeping pets out of bedrooms, removing carpeting and other dust-mite havens and opening windows, the magazine says.
2. Electrostatic precipitators: They apply an electrical charge to particles and deposit them onto filters. They commonly emit small amounts of ozone as a byproduct. This month, Consumer Reports withdrew its endorsement of them after 15 years of recommending some models, saying, “We now believe that air purifiers that emit even small amounts of ozone are not your best choice.”
Ozone is a common air pollutant, an indicator of smog’s presence. The Environmental Protection Agency says that relatively low ozone levels can cause respiratory problems.
3. Ozone generators: Manufacturers say that ozone will purify the air, but Consumer Reports recommends against such machines, saying its tests have found that their ozone production generally exceeded federal Food and Drug Administration limits of 50 parts per billion set for medical devices. The California Air Resources Board just approved new rules, requiring such generators to limit ozone to 50 ppb by Dec. 31, 2008.

Newer houses with better insulation, double-paned windows and weatherstripped doors save energy, but they also seal pollutants into our homes. I try to limit my impact on the environment. Air cleaners are just another electronic device to run, with uncertain results. My choice is to vacuum and wash floors and bedding regularly and to open windows daily. Those are results you can see.