HEPA® is an acronym for 'High Efficiency Particulate Air'. HEPA® filters originated as far back as the 1940's, and were introduced commercially in the 1950's under a registered trademark.
A 'true HEPA®' is the most common filter. It is defined as being able to remove at least 99.97% of particulates such as dust, animal dander, smoke, mould and other allergens that are 0.3 microns or larger, from the air and thus improving air quality.
Products such as our AP281 and HM69901-RC air purifiers incorporate true HEPA® filtration cartridges.
HEPA® filters cannot be cleaned and must be replaced after a certain amount of time. Once they are blocked the air will not pass through them and they become ineffective. It is important to follow the manufacturer's recommendations as to how often to change these filters. In particularly dusty/dirty environments you may have to change the cartridges more frequently.
2 June 2009