Knowledge of the use of HEPA filters
First of all, we would like to remind customers that the most fundamental and simplest way to extend the service life of the HEPA filter is to keep the dust out of the pre-filter. In other words, ensure that the air flow exposed to the HEPA filter is the air filtered by the pre-filter, coarse filter and medium filter. The air at this time should meet the standard of 99.95% small dust particles and low pollution.
It should be noted here that replacing the pre-filter generally does not require stopping production or other normal work plans and arrangements. After installation, it can ensure the normal operation of air conditioning equipment without debugging. So experienced customers will focus on the pre-filter. For highly clean areas such as class 10000 and class 100000 clean workshop or operating room, F8 filtration can be selected for pre-filtration (colorimetric method 95%).
In this way, the service life of the terminal HEPA filter can generally reach 5 years. In foreign projects and domestic new projects. F8 filters are the most common prefilters for non-uniform flow cleanrooms. For the clean workshop of class 100, class 10 or higher in the chip factory, the common efficiency level of the pre-filter is H10 (MPPS85%), and many new projects simply choose HEPA (filtration efficiency of 0.37m particles ≥99.97%). In the past clean room air conditioning system design in China, the common configuration of the filter is: coarse effect → medium effect → high efficiency. At that time, the service life of terminal HEPA filters was only 1-3 years, with the worst being a few months. It can be seen that the pre-filtration efficiency determines the service life of the end filter.
In some cases, the provisions for the use of SFFILTECH high efficiency filters are not out of consideration of resistance, but other factors. If there is hydrofluoric acid in the workshop, and the workshop air conditioning is not a full fresh air system, the glass fiber filter paper of the high efficiency filter will be corroded by the return air. For safety, the HEPA filter must be replaced regularly. At present, some of the third class A hospitals and pharmaceutical factories in China take the initiative to replace the HEPA filter after the rainy season every year, the main purpose is to prevent any possible mold pollution on the filter.
In some countries, third class A hospitals, biological laboratories of pharmaceutical factories and laboratories dealing with dangerous goods will use new HEPA filters in order to ensure safety and reliability before carrying out a new health topic.