Filters- Some air purifiers clean the air by having it pass through a filter to remove particles.
These are sometimes called air cleaners. In households, these filters are usually part of the heating or cooling system AND are only effective when A/C system is running.
Ionizing Purifiers- These air purifiers use a method called corona discharge to create charged molecules called ions.
The corona discharge is a small but intense electrical field. Molecules passing through it will pick up an additional electron, giving the molecule a negative charge. Once a particle is charged, it will be attracted to anything with the opposite charge.
Ozone Generators- An ozone generator works much like an ionizing purifier, but it is designed to alter molecules of oxygen and turn them into ozone, a molecule made up of three oxygen atoms. While most of this oxygen recombines into dioxygen, some atoms create ozone. Home should be vacated, during treatment.
Adsorbents- Many purifiers incorporate an adsorbent material to soak up odors, fumes, and chemicals in the air.
Adsorption (not absorption) is the process of one substance being trapped on the surface of another substance. The most common adsorbent is activated charcoal, which is extremely porous. Larger particles are simply stuck in the many pores in the charcoal. Electrostatic attraction draws some substances into the pores. Certain substances react chemically with the charcoal and bond to it. The high surface area of the charcoal gives it significant bonding places. The process used to make the charcoal can affect which compounds it is better at absorbing.
UV Light- Ultraviolet radiation renders certain micro-organisms sterile (and harmless).
Some air purifiers feature a UV light that bathes the air as it passes through, eliminating the potential harm of airborne bacteria and viruses.
The following links will provide you with additional information on indoor air purification products and methods to keep your home healthy.