The applicable range of high-efficiency filters

The application scope of high-efficiency filters mainly covers industries such as electronics, semiconductors, precision machinery, pharmaceuticals, hospitals, and food, where there is a high demand for cleanliness in medical, civilian or industrial clean areas.
Since high-efficiency filters are generally used as the final stage of filtration, they have the strictest requirements. Of course, additional "attention" is needed.
Firstly, we need to remind customers that to extend the service life of high-efficiency filters, the most fundamental and simplest method is to keep the dust outside the pre-filter. That is to say, ensure that the air flow that the high-efficiency filter comes into contact with is the air that has been filtered by the pre-filter, the coarse filter, and the medium filter. At this time, the air should meet the standard of 99.95% for smaller dust particles and lower pollution.
It should be noted here that replacing the pre-filter generally does not require production suspension or the cessation of other normal work plans and arrangements. After installation, it can ensure the normal operation of the air conditioning fresh air equipment. Therefore, experienced customers will focus their attention on the pre-filter. For clean rooms of 10,000 and 100,000 grades or operating rooms in highly clean areas, the pre-filter can be selected as F8 filtration (colorimetric method 95%). In this way, the service life of the end high-efficiency filter can generally reach 5 years. In foreign projects and domestic new projects, F8 filtration is the most common pre-filter in non-uniform flow clean rooms. For clean rooms of 100 and 10 grades or higher in chip factories, the common efficiency level of the pre-filter is H10 (MPPS 85%). Many new projects simply choose HEPA (filtering efficiency ≥ 99.97% for 0.37m particles). In the past design of clean room air conditioning systems in China, the common configuration of filters was: coarse → medium → high-efficiency. At that time, the service life of the end high-efficiency filter was only 1-3 years, and the worst was only a few months. It can be seen that the efficiency of the pre-filter determines the service life of the end filter.
In some cases, the regulations for the use of high-efficiency filters are not due to the consideration of resistance, but other factors. If there is hydrofluoric acid in the factory and the workshop air conditioning is not a fresh air system, the glass fiber filter paper of the high-efficiency filter will be corroded by the return air. For safety, efficient filters must be replaced regularly. Currently, some tertiary grade A hospitals and pharmaceutical factories in China will actively replace high-efficiency filters after the rainy season each year. The main purpose is to prevent any possible mold contamination on the filter. Some tertiary grade A hospitals, pharmaceutical factories, biological laboratories, and laboratories dealing with dangerous substances in some countries will use new high-efficiency filters before conducting a new important project to ensure safety and reliability.