Inefficient filterReplace every 1-3 months, medium-efficiency filters are replaced every 3-6 months, and the service life of high-efficiency filters in class 10,000 and class 100,000 clean rooms can be replaced every 2 years. Depending on the usage environment, if the filter cannot reach the specified cleanliness at maximum load, the filter must be replaced.
For a running clean room, the value of the terminal high-efficiency filter is not high. The total value may be less than the user’s output value for a few hours, but the risks and indirect costs of replacing the terminal high-efficiency filter will be high. When replacing the filter, production must be stopped. Only the owner can calculate the loss caused by the stoppage of production. This loss is definitely higher than the cost of spare parts for the filter. Replacing a high-efficiency filter is a very careful operation. Everything in the clean room may be valuable. The cost of destroying one component may be higher than the cost of the entire filter. After replacing the filter, it must be inspected by professionals, and sometimes the air conditioning system must be debugged and undergo a period of trial operation. The three costs of testing, debugging, and trial operation added together may be comparable to the price of the filter. Smart owners always want to extend the service life of high-efficiency filters as much as possible, not to save a few dollars on the filter, but to avoid a lot of trouble caused by replacing the filter.
To extend the service life of a high-efficiency filter, the most fundamental way is to block dust in the pre-filter. Replacing the pre-filter generally does not require shutdown or debugging, so experienced owners will spend their attention and money on the pre-filter and protection-level intermediate filter. For 10K and 100K clean workshops, G4 is used for pre-filtration, and F8 filter (colorimetric method 95%) is used for intermediate filtering. In this way, the service life of the terminal high-efficiency filter can generally reach 5 years. In foreign projects and domestic new projects, F8 filter is the most common pre-filter in non-uniform flow clean rooms.
In some cases, the service life of high-efficiency filters is not determined by resistance, but by 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 in the high-efficiency filter will be corroded by the return air. For safety, the high-efficiency filter must be replaced regularly. Some large pharmaceutical factories need to replace high-efficiency filters every year after the rainy season in order to prevent any possible mold contamination on the filters. Some biological laboratories and laboratories dealing with dangerous goods will require the use of new high-efficiency filters for reliability before starting a new important project.
However, in order to protect the use of post-stage high-level filters and ensure the safe operation of clean rooms, many smart owners replace primary-efficiency filters every month, and replace medium-efficiency and sub-efficiency filters every 3 months (or As mentioned earlier, a high-efficiency filter is used as a protective filter in the final section of the wind cabinet), which can ensure the service life of the high-efficiency filter for more than 5 years (or even 10 years). Moreover, because the new filter has small resistance after replacement, the air-conditioning load is greatly reduced. The cost of filter replacement is far less than the electricity bill required to operate the air conditioner. Frequent replacement of the front-stage pre-filter actually allows the air conditioner to operate under a low resistance load, saving a lot of electricity bills.
Of course, high-efficiency filters are also affected by the quality of their own product auxiliary materials, such as the adhesive force of the filter adhesive. If the adhesive force of the glue is insufficient, the filter paper and metal frame will fall off over time, which will also affect the service life of the high-efficiency filter.