Air filter grade efficiency division and final resistance standard value

29/07/2020

The final resistance is a standard to measure the service life of an air filter. The resistance of a new filter is called the "initial resistance", and the resistance corresponding to the scrapped filter is called the "final resistance". The filter forms resistance to the airflow, the filter accumulates dust, and the resistance increases. When the resistance increases to a certain specified value, the filter is scrapped. The lower the initial resistance of the air filter with the same requirements, the better, the following will introduce the following standards for the resistance value of the primary, middle, and high-efficiency air filters:

   

    Recommended final resistance value:

 G3 (initial effect) 100~200Pa

    G4 (junior high efficiency) 150~250Pa

    F5~F6 (medium efficiency) 250~300Pa

    F7~F8 (high and medium efficiency) 300~400Pa

    F9~H11 (sub-high efficiency) 400~450Pa

    High efficiency and super high efficiency of 400~600Pa

    The choice of final resistance is directly related to the service life of the filter, the range of system air volume changes, and the system energy consumption. In most cases, the final resistance is 2 to 4 times the initial resistance. The dirtier the air filter is, the faster the resistance increases. A too high final resistance value does not mean that the service life of the filter will be significantly extended, but it will make the air volume of the air conditioning system drop sharply. Therefore, there is no need to set the final resistance value too high.

    Low-efficiency air filters often use coarse fiber filter materials with a diameter greater than or equal to 10 microns. Due to the large gaps between the fibers, excessive resistance may blow away the dust on the filter. At this time, the resistance will no longer increase, but the filtration efficiency will drop to zero. Therefore, the final resistance value of filters below G4 must be strictly limited. Each filter section should be equipped with resistance monitoring devices. The final resistance depends on the instrument to determine, not just the operator's feeling.

    Air filter efficiency classification

    G1 40% 5μm

    G2 65% 5μm

    G3 85% 5μm

    G4 90% 5μm

    F5 45% 1~5μm

    F6 65% 1~5μm

    F7 85% 1~5μm

    F8 90% 1~5μm

    F9 95% 1~5μm

    H10 95% 0.3μm

    H11 99% 0.3μm

    H12 99.9%0.3μm

    H13 99.95-9%  0.3μm   Generally speaking, it is 4 9s, and strictly speaking, it is 3 9s 5

    H14 99.995-9% 0.3μm  Generally speaking, it is 5 9s, and strictly speaking, it is 4 9s 5

    U15 99.9995%  0.12μm

    U16 99.99995%  0.12μm

    U17 99.999995%0.12μm