"HEPA" is the  abbreviation of "High Efficiency Particulate Air Filter". HEPA is widely used to clean up the air purifying and filtering in many fields such as radiation pollution, microcrystal parts assembly and hospital operating room.Depending on the size of the pollutant particles, HEPA can be divided into different grades.The medical grade HEPA is a high grade HEPA filter, which can filter the tiny particles above 0.3 microns in the air (most bacteria have the diameter of > 0.3 microns in diameter), and the purification efficiency can be up to 99.97%.So HEPA is currently recognized in the world, can effectively filter the air of allergens, can reduce the incidence of asthma and allergies, the best air purification filter.
Selection Points
1.The main control parameters of HEPA filter are filtration efficiency, rated air volume, initial resistance under rated air volume, dust holding capacity and so on.
2.According to GB/T6165-1985 "standard test method for performance of high efficiency particulate air filter through the prescribed rate and resistance" test, the penetration rate is less than or equal to 0.1% (i.e. efficiency higher than 99.9%) or count on the particle size of more than 0.1 M particles through the ratio of 0.001% (i.e. efficiency higher than 99.999%) filter is a high efficiency air filter.
3.Efficient air filter commonly used filter materials such as superfine glass fiber.
4.The air filter shall meet the requirements of fire protection. The HEPA filter shall be divided into three grades according to the degree of fire resistance: the 1 stage filter, all the materials of the filter are non inflammable, and the non inflammable material shall comply with the GB8624-1997 Grade A. 2 stage filter, filter material should be in line with GB8624-1997 grade a non flammable material, partition board, frame available in line with GB8624-1997, B2 grade flammable materials. 3 stage filter, filter all materials available, in line with GB8624-1997, B3 level
5.At design time, the final resistance is two times of the initial resistance, and the resistance is calculated as the filter.
6.The initial resistance of HEPA filters shall not exceed 10% of the resistance of the product samples.
7.High efficiency air filters should not be used alone, and HEPA filters should be installed at the end of the air conditioning system.
8.Dust capacity manufacturers should provide. HEPA filter should leak test when leaving factory. Other requirements are determined according to user requirements.
9.In a general non parallel flow clean air conditioning system, a combined filter outlet is adopted.