Hepa Air Purifier

HEPA, is an odd-sounding acronym that is shorthand for “High Energy Particulate Arresting” filter. HEPA is pronounced with short "e" as in pep club: heppa.

The HEPA air filter is the air purifier industry standard, despite air filtration with technologies other than HEPA which are selling well. The HEPA air filter, where properly deployed, has a long record of safety and effectiveness.

HEPA is an efficiency standard for air filters, not a brand name.

To qualify as HEPA, the filter must remove 99.97% of particles as small as to 0.3 microns from air that passes through it. Notice what the previous sentence did not say: “remove 99.97% of particles that pass through the air purifier.”

Purifier efficiency is the percentage of particles in a given size class removed from the air passing through the purifier.

So efficient HEPA air filters can be packaged in cheap materials to create a mass market "HEPA air purifier." Many a HEPA air purifier fails to provide promised performance. The main cause is ill-fitting housings and cheap gaskets which allow air to leak past the filter media.

A powerful fan forces air through the HEPA filter, creating high pressure on the intake side.

In poorly sealed and gasketed air cleaning systems, the increased air pressure forces dirty air to squeeze through cracks around the filter media, and spew un-filtered back into the room. This is called "bypassing."

Over time, bypassing air purifiers build up a layer of fine dust in the exhaust outlet. Turn them on, get sprayed with dust: what air purifier?

The HEPA air filter is measured in square feet of fiber reinforced pleated paper. More is better, like 50 to 80 square feet.

Many filters which do not qualify as true HEPA are disguised by terminology: HEPA-type, or HEPA-like. Air purifiers which match the efficiency standards by other means may even use the "H" word on their products: HEPASilent.

HEPA air filters are a basic building block of most serious air purifiers. A few good air purifiers without HEPA do exist, the Blueairs come to mind. The best residential HEPA filters come in IQAir air purifiers, worth investigating even for those who could never afford one.

Once you understand how the premium models are built, you'll never buy a cheap air purifier with a HEPA-type filter banging around loose inside.

Click for the web's best Air Purifier Reviews. The Author, Ed Sherbenou, is an experienced air purifier user, with 40 years of direct experience due to chemical sensitivity and severe allergies. He writes indoor air quality articles, posts blogs,and maintains a leading air purification website:

http://www.air-purifier-power.com