Air conditioner filter life
For the clean room in operation, the value of the high-efficiency filter at the end is not high, and it may not add up to the output value of the user for a few hours, but the risk and overhead of replacing the high-efficiency filter at the end will be high. When the filter is replaced, production must be stopped, and the loss of production stoppage can only be calculated by the owner himself. This loss is definitely higher than the cost of spare parts for the filter. Replacing a high-efficiency filter is a very careful operation. Anything in a clean room can be expensive, and the damage to one part can be higher than the cost of all filters. After the filter is replaced, it should be inspected by professionals, and sometimes the air-conditioning system must be debugged, and it will take a period of trial operation. Testing, debugging, trial operation, the three costs are added together, which may be comparable to the price of the filter. Smart owners always want to prolong the life of the HEPA filter as much as possible, not to save a few dollars on the filter, they want to avoid a bunch of troubles caused by replacing the filter.
To prolong the service life of the high-efficiency filter, the most fundamental way is to block the dust in the pre-filter. Replacing the pre-filter generally does not require production stoppage and debugging, so experienced owners will spend their attention and money on pre-filters and protective intermediate filters. For Class 10K and Class 100K clean workshops, G4 filters can be used for pre-filtration, and F8 filters (95% colorimetric method) can be used for intermediate grades. 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 filters are the most common pre-filters in non-uniform flow clean rooms.
In some cases, the service life of high efficiency filter is not based on the consideration of resistance, but other factors. If there is hydrofluoric acid in the workshop, and the workshop air conditioner 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. In some large pharmaceutical factories, high-efficiency filters are replaced every year after the rainy season in order to prevent any possible mold contamination on the filters. Some biological laboratories and laboratories dealing with hazardous materials will require the use of new high-efficiency filters for reliability before undertaking a new important topic.