Absolute filters guarantee the very highest level of air quality. The filtration class of HEPA filters is from EU 10 to EU 14, and then from EU 15 to EU 17 there are ULPA filters.
Such filters can prevent particles, aerosol, fine toxic dust, virus, bacteria, etc from invading into rooms, where air quality must be at the very best possible level.
History of HEPA. HEPA (High Efficiency Particulate Air) is the first micro filter standard that was designed during World War II by the United States Atomic Energy Commission. For catching radioactive contaminants from nuclear power testing laboratories the filters had to be able to remove at least 99.97% of particles 0.3 µm in diameter. Today, HEPA filter is more broadly applicable. In addition to purifying the contaminated air of nuclear power stations, there are many new usage possibilities in medicine, electronics, optics, and food industry, in science laboratories and in the social sphere.
The construction of a HEPA filter consists of a very thin and dense filter material folded into a wooden or metal frame. The filter material catches particulates of dust from the air that penetrates it. High filtering ability is achieved by very low speed at which the air penetrates the filter material. Maximal speed can not exceed 0.025 m/s. To achieve sufficient air speed through the face of the filter, it is necessary to fold the filtering material into the cassette as tightly as possible, but at the same time it should be noted that the filter resistance would not become too high. In a standard filter cassette in size 610 x 610 x 292 mm has c.a. 20 m² of filter material. The most used material is glass cloth, but also different fabrics of synthetic fibre can be used.
It is possible to produce filter material in one piece with width 1220 mm, length 1830 mm and fold depth up to 280 mm.
There are different versions of the filter, which are all rustproof, easy to install and clean. We offer HEPA filters in standard sizes, with depths: 69 mm, 78 mm, 150 mm, 292 mm.
All filters have been tested according to the norms of FDA 175.105 (U.S. Food And Drug Administration).
Usage areas of HEPA filters
There are many usages areas for HEPA aka bacteriologic filters: food, optics, and electronics industry, hospitals, laboratories, sterile rooms, etc.
ULPA (Ultra Low Penetration Air) filters with higher cleaning level were developed in the 1970s. These filters remove at least 99.999% of particles 0.12 µm in diameter. ULPA-filters resemble HEPA-filters in their construction; the main difference is in higher level of cleaning. With this filter the air can be purified of the smallest particles, even viruses.