Ozone generator units introduce small quantities of ozone into the air to reduce airborne pollutants. Unlike the filtering systems, ozone generators actively work to "clean" the air.
While there is good evidence that using ozone for water purification methods have helped reduce contaminants without creating negative side effects, introducing ozone into the air of a living space can be a concern.
Some manufacturers use the terms "trivalent oxygen" or "saturated oxygen" as euphemisms for ozone, and it's important to be aware that some ozone generators are developed for industrial use. For example, ozone generators can be extremely useful in controlling microbes in meat storage.
However, high concentration levels required for contaminant control are in conflict with potential health effects established by authorities such as the National Institute of Occupational Safety and Health (NIOSH), the United States of America's EPA, and the U.S. Food and Drug Administration (FDA).
Note that the FDA has established that any output of ozone by a device greater than .05 ppm is unsafe to use in any place with human occupancy. Ozone is a potent lung irritant and exposure to elevated levels can be especially dangerous for persons with asthma and other chronic lung diseases.
Therefore, if you want to use an ozone generator to remove smells or contaminants from the air, you need to realize that they are either dangerous or ineffective when used in an dwelling areas. This is because ozone is ineffective at levels that aren't harmful to humans and more effective at levels that are dangerous to people. They are used in places like crime scenes to clean the air while the area is unoccupied, in this capacity they are useful.
Further complicating things is that ozone generators, even when used according to the manufacturer's guidelines produce inconsistent amounts of ozone, so how do you know when too much has been released into the air? Why take chances?
Your health is more important and there are safer ways to clean the air in occupied areas.