HEPA filter grade

1.HEPA filter grade

According to the EU EN1882 standard, according to the filter efficiency, we divide HEPAl filter into five grades: coarse filter, medium filter, sub-high filter, HEPA high-efficiency filter and ultra-high-efficiency filter. When the filtration efficiency of 0.3 um particle size is higher than 99.9%, the filter is called H12.

The national standard requires that the filtration efficiency of HEPA material is above F9. But as the grade rises, the stronger the purification capacity, the greater the wind resistance. Therefore, under the same conditions, the higher the HEPA level, the lower the CADR value of the air purifier.

2.How often does the HEPA filter change?

The core index of judging the service life of the filter is the dust capacity. The core data affecting dust capacity is the extension area of the filter. The larger the extension area of the filter, the higher the dust capacity, the more durable the filter will be. Dust capacity refers to the amount of dust deposited when the resistance due to dust deposit reaches the prescribed value (usually twice the initial resistance) under the action of a certain air volume. (If it's too troublesome, HEPA filters can normally be used for 6-12 months in a few days, depending on the local air quality.)

3.Why is it sour?

In fact, this is the problem of most filter air purifiers.

Because when the air purifier is working, the particulate matter and microorganisms in the air will be adsorbed on the filter. At the appropriate temperature and humidity, the filter will breed bacteria and produce odor. In addition, the activated carbon filter in the air purifier also produces sour taste after dampness.

4.Why can't HEPA filter be washed?

Replacing the filter element is the most direct way, but some friends worry that the cost of replacing the filter element once is too high. Indeed, HEPA filters for air purifiers can be sold at prices ranging from 200 to 1000 yuan. There are many kinds of HEPA filter material, which can be divided into PP (polypropylene) high efficiency filter paper, PET filter paper, PP and PET composite high efficiency filter paper and glass fiber high efficiency filter paper. PP (polypropylene) is paper, so it can not be washed.

Another part of HEPA filters is made of PET or PTFE, which is the origin of many online claims that HEPA filters are washed in water. However, such HEPA filters are inefficient and are not recommended for use.