Can you explain how an ozone generator (air purifier) works? Can ionizing actually clean the air? We recently purchased such a unit. Did we do the right thing?
What are the advantages of using a carbon filter rather than a cheaper electrostatic filter?
Why offer a UV lamp on an air purifier?
Can you explain what the difference the fan speed makes to the cleaning effectiveness of a machine?
Are there any benefits to using a room air cleaner as opposed to a central HEPA or electrostatic system?
We often get people who want to move an air cleaner from room to room during the week - one day one room and then move onto the next.

Q: Can you explain how an ozone generator (air purifier) works? Can ionizing actually clean the air? We recently purchased such a unit. Did we do the right thing?
A: The "air cleaner" that you describe is actually two different devices in one package. It consists of a component that generates ozone(O3) which is supposed to remove odor-producing chemicals as well as organic compounds such as formaldehyde and a variety of solvents. The ionizer part produces either positively or negatively-charged ions which become attached to dust particles and various building surfaces. The ionizing module is supposed to remove airborne dust particles from the air of your home.
Such devices are widely sold and are highly controversial. Legal action has been filed by several State Attorney's General with one high profile case in trial at this moment.
There are several major issues associated with such devices. The primary one is that O3 is a very toxic substance that poses health risks to those exposed. Should manufacturers be selling a device to consumers that may injure their health as well as other family members? The other major issue (associated with O3 generators) is that they are not effective in controlling contaminants as claimed.
Ozone is a potent respiratory irritant even at low concentrations (> 0.10 ppmv) if the exposure occurs over a period of hours. If an O3 generator/air purifier is limited to O3 production below the level that the Food and Drug Administration (FDA) requires ( 0.05 ppmv), there is no way that there would be enough O3 in your home to "remove" the chemicals that the "air cleaner" is theoretically designed to do. It is impossible from a chemistry standpoint.
When O3 reacts with chemicals in air, new chemical substances are produced that are generally more toxic than those already present (the law of unintended consequences). In addition, O3 has a variety of effects on materials. It has the bleaching power of chlorine (on a molecule-to-molecule basis). As such it reacts with fabric dyes in carpeting, upholstery, etc. Ozone has been reported to turn blue carpets green! Ozone also reacts with rubber compounds and soft plastics. Those cracked rubber bands in your desk - the low O3 levels in the atmosphere. It attacks rubber/plastic gloves, rubber/plastic gaskets/ O rings, washers, vinyl materials, etc. and cracks them. Adding O3 to your house with your "air cleaner" will accelerate this process.
As you can see using an O3 generator as an "air purifier" is a horrible idea. They are a waste of consumers' money and a potential threat to the health and safety of your family (as well as a threat to your possessions). More information on O3 and O3 generators can be obtained from USEPA's website: www.epa.gov/iaq/pubs/ozonegen.html
The second module in your air cleaner is an ion generator. Fortunately, it poses no health risks to you or your family. Under the best operating conditions (in a closed bedroom), they can be moderately effective in removing airborne dust particles. Such dusts will plate out on walls and other room surfaces. The air becomes somewhat cleaner; your walls somewhat dirtier. AllergyBuyersClub.com

Q: What are the advantages of using a carbon filter rather than a cheaper electrostatic filter?
A: While electrostatic filters help collect dust particles, they cannot remove chemicals and odors from the air. An activated carbon filter actually traps chemicals, gases and odors; this combined with a HEPA filter offers you the most efficient air purification possible. Granulated Activated Carbon (GAC) has the strongest adsorption power of any material known to man. In one pound of carbon there are over 200 miles of tiny pores to trap gases and odors. It’s safe, cost efficient and so effective the military uses it in their gas masks! AllerAir

Q: Why offer a UV lamp on an air purifier?
A: A UV lamp offers the added benefit of sterilizing any bacteria, viruses or mold mycotoxins that may be present in the air. The UV actually destroys the reproductive DNA of these organisms. This kind of sterilization is highly effective and has been used in hospitals, laboratories and medical facilities since the 1930’s. AllerAir

Q: Can you explain what the difference the fan speed makes to the cleaning effectiveness of a machine?
A: The higher the fan speed, the more air is drawn into the machine, and the more clean air is distributed per hour back into the space. The purpose of an air cleaner is to clean the entire volume of air in the space, and clean it again, and again..remember, contaminants are continuously entering the air as we discussed before. LOW speed might clean a rooms air volume twice each hour, while HI speed on the same machine might clean it 6 times each hour. Especially to an allergy or asthma sufferer, the highest amount of clean air is the best. Interview with William Schuettenberg, Vice President, Healthway Products AllergyBuyersClub.com

Q: Are there any benefits to using a room air cleaner as opposed to a central HEPA or electrostatic system?
A: A central forced heat or air conditioning system generally has a filter that is not high efficiency and is not very dense; so only larger particles may be captured. Larger particles are seldom the issue for respiratory problems, it is the smaller ones that can get into your lungs, and cause reactions and trigger breathing attacks. I always recommend that consumers use at least a middle grade efficiency filter in their central system, to get some smaller particles. Central systems do not clean rooms at a high level because they do not set up a strong enough air current in the room to get all the air space "scrubbed" and then back though the central filter system. To have the best indoor air quality, use a good, middle grade central filter, along with a high efficiency room air cleaner for the spaces of greatest health concern. Interview with William Schuettenberg, Vice President, Healthway Products AllergyBuyersClub.com

Q: We often get people who want to move an air cleaner from room to room during the week - one day one room and then move onto the next.
A: I have been asked this question many times. I find that people get the highest satisfaction from their air cleaner when they focus its ability to clean, in a single indoor space. By that I mean, ask yourself where do you spend the most time, or do you have trouble sleeping at night, does your office environment give you problems you don't have in other spaces, etc. Pick a target area and do an excellent job in that space, continuously. Approximately 30% of people who start by purchasing one air cleaner, buy another one because they discover "it works" in a specific space, when they leave it on continuously. Interview with William Schuettenberg, Vice President, Healthway Products AllergyBuyersClub.com