An air filter is a device composed of fibrous or porous material that removes solid particles such as dust, pollen, mold, and bacteria from the air. Filters containing adsorbents or catalysts also remove odors and gaseous pollutants. Air filters are generally used in clean workshops, laboratories and clean rooms, or for dust prevention of electronic mechanical communication equipment. There are many types of filters. It is mainly divided into primary filter, intermediate filter, high efficiency filter and sub-high efficiency models. Various models have different standards and performance.

