The air filter should be able to remove up to 99.97% .3 micron size particles from the air. If HEPA was a basketball player then he would basket the ball 9977 times every 10,000 shots she/he was given – :). At the same time it means that smaller particles are also removed but at a lesser percentage level.

Before delving into how can air purifiers help in allergies, dust and asthma, lets understand three things. One- What is an allergy? Second – What is Asthma? Third – What substances are responsible for allergies and asthma?

There can be many techniques employed to purify the air. Most air purifiers use one or more combinations of these techniques and technologies to purify the air around us. Let’s have a look at what are the technologies available to remove these contaminants from air.