What is the difference between high-efficiency air filters and ordinary primary filters?

High-efficiency air filters and ordinary primary filters differ in the following aspects:
Filtration efficiency
High-efficiency air filter It can efficiently filter out tiny particles larger than 0.3 microns, with a filtration efficiency typically reaching over 99.97%, and can even reach 99.999%. It can effectively intercept tiny pollutants such as bacteria, viruses, and pollen, and is often used in places with extremely high air cleanliness requirements, such as hospital operating rooms, pharmaceutical workshops, and electronic chip manufacturing workshops.
Ordinary primary filter: Mainly used for filtering large particles of dust, hair, debris, etc. larger than 5 microns. Its filtration efficiency is relatively low, generally around 40% to 80%. It is often used for the primary filtration of air conditioning systems and in some places with low requirements for air cleanliness, such as ordinary offices and shopping malls.
Material and Structure
High-efficiency air filters: Typically, superfine glass fiber paper or synthetic fibers are used as filter materials. These materials feature small fiber diameters, high porosity, and large specific surface areas, which can form complex maw-like air flow channels, making it easier for tiny particles to be intercepted and adsorbed. Its structure is generally compact, and usually, multiple layers of filter media are superimposed to increase the filtration area and filtration effect.
Ordinary primary filters: The filter materials are mostly polyester fibers, non-woven fabrics, etc. The materials are relatively thick and have large pores to allow larger dust particles to pass through and perform initial interception. The structure is relatively simple, usually a single layer or a few layers of flat or folding structure, to reduce costs and facilitate cleaning or replacement.
Resistance characteristic
High-efficiency air filters: Due to their high filtration accuracy and small pores, the resistance to air passing through is relatively large. As the usage time increases, the number of intercepted particles gradually increases, and the resistance will keep rising. When the resistance reaches a certain level, the filter needs to be replaced in time to ensure the normal operation of the ventilation system.
Ordinary primary filter: It has relatively large pores, smooth air circulation, and low initial resistance. However, during the process of filtering large particles of dust, dust will gradually accumulate, causing resistance to increase. Nevertheless, the rate of resistance increase is relatively slow, and the replacement cycle is relatively long.
Service life
High-efficiency air filters: Due to their high filtration accuracy, they are prone to clogging by tiny particles, so their service life is relatively short, generally 1 to 3 months, depending on the usage environment and frequency. In some severely polluted environments, replacement may be required more frequently.
Ordinary primary filter: Mainly filters large particle impurities, is not prone to clogging, and has a relatively long service life, usually 3 to 6 months. If the usage environment is good and the usage frequency is low, its service life can be further extended.
Application scenarios
High-efficiency air filters: They are widely used in places with extremely high requirements for air cleanliness, such as aseptic production workshops in biopharmaceutical factories, intensive care units in hospitals, and electronic semiconductor manufacturing workshops. These places need to strictly control the number of microorganisms and dust particles in the air to ensure product quality or patient safety.
Ordinary primary filters: They are commonly used in the ventilation and air conditioning systems of general industrial and civil buildings, such as office buildings, shopping malls, hotels, etc. As pre-filtering devices, they can protect the subsequent medium and high-efficiency filters, extend their service life, and also provide basic air purification for the room, reducing the impact of large particle dust on human health and equipment.