There are many different types of air cleaners on the market, including hybrids of the various types, but all fall under two broad headings, arrestors and non-arrestors. Under these we can find the five most popular: High Efficiency Particle Arrestor (HEPA)/mechanical air cleaners, ionic air cleaners, ultra-violet air cleaners, ozone air cleaners, and electronic air cleaners.

Mechanical and electrostatic air cleaners are arrestors, and the others are non-arrestors. Arrestor air cleaners work by attracting the pollutants into the filter thus trapping them. Non-arrestors work by either killing the pollutants, bacteria, molds or by causing them to stick to charged surfaces.

Arrestors

HEPA filter air cleaners were developed to capture radioactive dust in the environment so as to protect scientists during WWII. The technology has been refined for modern use in both homes and businesses. HEPA filters can trap most allergy-causing agents: dust mites, cigarette smoke and chemical odors to name a few.

Mechanical filters can be portable or centralized. Centralized systems are installed inside central heating and air-conditioning systems.

Electrostatic filters use the principle of opposite poles attracting, thus pulling particles into the charged plates designed to collect and hold air-borne contaminants.

Non-Arrestors

Ionic air cleaners, also known as electrostatic air cleaners, produce an electric charge that forces air borne particles onto furniture, walls and other surfaces, thus effectively removing them from the air you breathe. These are only available as portable units, so they are ideal for residential purposes. Ionic air cleaners release ozone into the air so they should be used with care.

Electronic air cleaners, purify the air by utilizing an electric current to trap air-borne pollutants. These types can also be installed in central heating and air-conditioning systems.

The main purpose of ultra-violet air cleaners is not to remove particles from the air, but to kill bacteria and molds. It does this by pulling the air inside where the bacteria and molds are zapped by the powerful ultraviolet rays.

Hybrid devices use a combination of any of the above filters to clean the air. There are single room air cleaners as well as cleaners that work for the entire house.