I use air cleaners in every room of my house and office and believe them to be truly beneficial. Also not one of my staff developed a cold this winter, which I find truly amazing. All I can do is warn consumers to stay away from any air cleaner that does not include a hepa filter. Anything that does not contain this kind of filtration media, is not particularly efficient at best and the worst are beyond comment. Ozone does not remove dust or particles from the air.
Ozone is used primarily in odor reduction after fires or smoke damage.
Ozone is a health hazard as documented by the American Lung Association so should only be used when human beings are out of the area. Some air cleaners create ozone, which is meant to break down gases and odors. The EPA warns to use ozone as means of cleaning the air in residential and office environments due to the irritant and potentially harmful nature of ozone. Some air cleaner manufacturers try to disguise the fact that their units produce ozone, by calling it activated oxygen. I think it is very hard for the average consumer to assess which air cleaner is the most effective.