HEPA and ULPA filters are both high-efficiency air filters that are similar in many ways, but there are some key differences that set them apart in terms of capturing airborne particles.

High-efficiency filters are widely used in various industries and applications that require clean air, such as pharmaceutical, electronics, food, and medical fields. However, different types and grades of high-efficiency filters have different initial resistances, which affect their performance and

As we all know, the highest filtration efficiency level of high-efficiency filters can reach 99.999995 or more for different particle sizes of pollution. In the past, there are always people who correspond the level of clean room with the efficiency level of high efficiency filter, and always think that the more 9 high efficiency filters are used, the cleaner the clean room can reach the cleanliness of 100 or even 10 levels. In fact, this concept is wrong, although the high efficiency filter is the core component of the clean room, but the clean room want to achieve 100 or even 10 levels of cleanliness, high efficiency filter is not the only condition. There are many factors affecting the cleanliness level of clean room, such as the number of air changes, door and window sealing, and personnel entering and leaving the air shower room.

Forklifts need to be used in plant E. At the initial stage, diesel powered forklifts were used because of their high power. But these diesel forklifts also cause problems with the filter. Incomplete combustion of multi carbon oxides is dispersed in the air, enters the air conditioning box through the return air, and condenses on the filter. We observed with a high power microscope and found that the condensate was in a semi flowing state on the primary and medium efficiency filters. Those agglomerates may migrate to the back of the filter material and volatilize due to uneven heating and humidification of the air, enter the HEPA filter downstream, and aggravate the blocking of the HEPA filter. Later, Factory E changed to use electric forklifts, which reduced the chemical pollution in the plant and also alleviated the filter blockage. ​

There is a ring of sealing gasket with good elasticity on the frame of HEPA filter, which closely fits with the high-efficiency air supply outlet. In the process of use, some maintenance and construction personnel will stand on the air outlet. If they are not careful, or the structural strength of t