Electronic air cleaners are effective in removing airborne particles, but not gases. One major drawback to many of them is that they can produce ozone that may irritate the lungs.

• Negative ion generators: These give a charge to airborne particles so that they become attracted to and settle on walls, floors, tabletops, draperies, people, etc. Activity within a room, however, may stir up and release these settled particles back into the air. Some devices have a collector to pull the charged particles back to the unit. If a unit does not have a collector, then this kind of a unit can result in the soiling of walls and other surfaces.

There are three types of air cleaners: mechanical filters, electronic cleaners, and hybrids that are a combination of these two.

Mechanical filtration: These draw air through a flat, pleated, or high efficiency particulate air filter to trap particles.
Some of the purposes of air filters are:

• Protect the ventilation equipment from dust and dirt
• Protect furnishings and décor of the occupied space
• Reduce housekeeping and building maintenance
• Reduce furnace and heating equipment fire hazards

In the search for clean indoor air, a three-tiered system is used:

• Control the source of pollutants at their source
• Provide adequate ventilation
• Clean the air

If all sources of indoor air pollutants are controlled, then there is no need to have air cleaners; controlling the source of the pollutants is obviously the first thing you want to do. However, not all sources can be controlled. Sometimes pollutants get in no matter how hard you try to prevent them. Therefore, the last line of defense is the air cleaner. Because of that, it should always be used in addition to, not in place of, the other steps!

Source: Air Quality Sciences: IAQ resource center
Updated May 24, 2002

Introduction

Three-tiered system for cleaner indoor air

Types of air cleaners:

Mechanical filtration

Electronic air cleaners

Mechanical-electronic hybrid filters

Styles of air cleaners:

Central filtration

Console-size units

Tabletop units

"Personal" air cleaners

Effectiveness

Ozone generators

What to know if you are thinking about buying an air cleaner

Press Release
Monday July 25, 7:50 am ET
Source: SEMCO Incorporated

This release was issued through eReleases(TM). For more information, visit http://www.ereleases.com.

COLUMBIA, Mo., July 25 /PRNewswire/ -- SEMCO Incorporated has received a prestigious "Top 100 Innovative Products" Award for 2005 from R&D Magazine for its Revolution(TM) System, an active desiccant-vapor compression hybrid rooftop unit.
The Revolution is a rooftop air conditioner that can independently control humidity and temperature while delivering any specified percentage of outdoor air into commercial and institutional buildings.