For the uninitiated, HEPA is an acronym for High Efficiency Particulate Air or Absolute. For many years these types of filters were called “absolute” filters because they basically captured absolutely all airborne particles that came in contact with the filter media.
HEPA filters are made from a special wet-laid material that has glass fibers as the basic material. It is then smoothed out like the making of paper and that is why the material is referred to as HEPA paper. It is also very fragile and can be cut or torn very easily.
HEPA filters have to meet a very stringent set of requirements before they can be labeled a true HEPA filter. They must be able to remove a minimum of 99.97% of all particles 0.3 microns or larger with a high efficiency below the 0.3 threshold. The media pack has to be sealed in a metal or aluminum frame and have a gasket on the downstream side to ensure complete sealing between the filter and the box or device in which it is placed.
HEPA filters are expensive. Very expensive and some of the new, higher efficiency filters like the ULPA or SULPA HEPA filters which are used in clean room applications and micro-chip manufacturing are 2 to 3 times more expensive than standard HEPA filters.
HEPA Type Filters are called that by competitors that don’t make true HEPA filters. These are filters that have a high MERV ratings. HEPA filters have a MERV rating of 20 while HEPA type filters have a MERV rating of 15. The difference is very big especially when you are talking about the removal of bacteria and viruses which is what true HEPA filters remove.
Pure Air Systems has been making HEPA based, fan powered air filtration systems since 1985. They use only true HEPA filters in their series of seven different air filtration devices. For more information on our complete line of HEPA and Carbon based filters please go to our website at: http://www.pureairsystems.com or call us anytime on our toll-free number at: 800-869-8025.