The term HEPA means High Performance Particulate Absolute or Air. This type of filter is used in many applications where the reduction and/or removal of fine, sub-micron airborne particles is required at a much higher efficiency than standard media filters like the ones used in air handling systems or HVAC systems. In order to qualify as a true, certified HEPA filter it must pass be able to have a rating equivalent to a MERV 17 or higher. This means the filter can capture 99.97% of all particles 0.3 microns or larger. Compare this to a MERV 5 or 6 filter which has an efficiency of less than 20% on particles larger than 10 microns in size.
A true HEPA filter is normally a pleated media filter with large pleats with separators or a mini-pleat with glue type separators and is enclosed in a metal housing.and is sealed with an industrial sealant. The metal housing has a gasket on one end of the housing which is normally placed on knife edge seal to eliminate any air bypassing the HEPA filter. The HEPA paper or filter media is fairly fragile and it also enclosed in a housing to protect the HEPA.
Because HEPA filter paper is very dense, the ability to pull air through the HEPA requires a larger motor/blower assembly as the pressure drop or resistance as measured in inches of water is much higher than the resistance through a standard throw-away furnace filter.Usually HEPA filters are mated with a blower/motor that is designed for this type of media, or they are enclosed is a housing like the ones Pure Air Systems makes that are stand-alone units with their own blower/motor and prefilters.
Pure Air Systems, located in Indianapolis, Indiana is one of a few companies in the U.S. that makes a high performance, certified HEPA, fan powered air filtration system that can be use in the residential, commercial, institutional, industrial and medical markets. These systems are designed to either be attached to any HVAC system in a partial by-pass configuration or as stand-alone units. They range in air flow from 50 CFM to 2,000 CFM.
For more information on our complete line of HEPA based air filtration systems please to go our website at: http://www.pureairsystems.com or call us on our toll-free number at: 800-869-8025.