According to the function and function, general general air filters can be divided into primary filters, medium efficiency filters and HEPA filters. Among them, the primary filter is mainly suitable for the primary filter of commercial or industrial ventilation and air-conditioning system or the pre-filter of ventilation and air-conditioning system for clean room, which can filter dust particles with a particle size exceeding 5μm. Medium-efficiency filters are mainly used in the intermediate-level filtration of air-conditioning systems, which can filter dust particles with a particle size of more than 1 μm. HEPA filters have good performance, and can be used as the terminal filter of the ventilation and air-conditioning system in clean rooms, and also as the intermediate filter of the ventilation system in places with high cleanliness requirements.

HEPA (High Efficiency Particulate air Filter) filter, namely high-efficiency air purifier, is a multi-layer purification technology, which can filter more than 99.97% of dust particles with a particle size of more than 0.3μm. It has the characteristics of long life and is widely used in semiconductor manufacturing factories, liquid crystal electronics factories, modular clean rooms and other occasions requiring ultra-high cleanliness.

Through chemical and physical adsorption, absorption and catalytic removal of pollutants (liquid, gas or suspended matter) in the air to achieve high efficiency and rapid air purification, it is mainly used in hotels and data centers and other commercial places that are sensitive to gas pollution.

The rapid development of air filters is closely related to the development of military and electronic industries. During the First World War, due to the use of various chemical agents, military gas masks with asbestos fiber filter paper as the smoke filter layer came into being. Fiberglass filter media for air filtration was patented in the United States in October 1940. In the 1950s, the United States conducted in-depth research on the production process of glass fiber filter paper, which led to the improvement and development of air filters; in the 1960s, HEPA filters came out; in the 1970s, HEPA filters using fine glass fiber filter paper as filter media The filter has a filtration efficiency of 99.9998% for particles with a particle size of 13 microns; after the 1980s, with the emergence of new test methods, the improvement of use evaluation and the improvement of filtration performance requirements, HEPA filters were found to have serious problems. problem, so a higher performance ULPA filter was produced.

The development of China's construction industry has greatly boosted the Chinese filter system market. New construction in residential, commercial, and industrial sectors has increased the demand for filter systems, which in turn creates the demand for filter system air filters. Building design innovations and focus on building energy efficiency have created good opportunities for filter system air filter manufacturers to expand their size in the market.

The growth of the overall market is driven by applications in the commercial and industrial segments, which together account for 90% of the total revenue. Among them, the applications in the industrial field are mainly from the energy and power industry and manufacturing, and the applications in the commercial field are mainly in government units, commercial real estate and medical institutions. Air filters for industrial use have occupied more than 60% of the market from 2013 to 2017. However, due to the continuous improvement of China's urbanization level and the development of the real estate industry, the proportion of air filters used in commercial real estate is also gradually increasing.