1、 The dust holding capacity per unit area of the filter material in the filter is too small;
2、 The filtration efficiency of the pre filter is low, and in addition, users have high expectations for the service life of the air filter.
To improve the previous issue, it is no more than to use a large area filter to extend its service life. It is recommended to consider this during project design. After the project is completed, it would be troublesome to modify the filter system to extend its service life. In many projects, users demand to minimize the occupancy of the air conditioning system as much as possible in order to save space, or users do not notice that suppliers use cheap filters with small filter areas in their pricing. During engineering acceptance, the filter can meet the requirements of air purification, but due to the small area of the filter material, the filtering effect of the filter is often poor after being used for a short time.
For the second reason, it is recommended to adjust the filtration efficiency of the pre air filter to block dust in the pre filter. For example, the end filter is F7, and when using G4 pre filter, the service life of the end filter is 3 months. After switching to pre F5 filter, the service life of the end filter is extended to half a year. In a clean room, the value of high-efficiency filters at the end is not high, but the risk and indirect cost of replacing the filter will be high, and replacing the pre filter does not require production shutdown. Therefore, experienced owners will pay attention and money to the pre filter. For clean factories with a grade of 10000 or 100000, F8 filters can be used for pre filtration, which generally results in a lifespan of up to 5 years for end efficiency filters. In the past design of clean room air conditioning systems in China, the common configurations of filters were: coarse efficiency, medium efficiency, and high efficiency. At that time, the service life of the high-efficiency filter at the end was only 1-3 years.