Air filter is the core equipment of air conditioning purification system, filter resistance to air, with the increase of filter dust, filter resistance will increase. When the filter dust is too much, the resistance is too high, will make the filter through the air volume is reduced, or the hepa air filter is locally penetrated, so, when the filter resistance increases to a specified value, the filter will be scrapped. Therefore, the use of filters, to master the appropriate cycle. In the case that the filter is not damaged, the service life is generally determined by the resistance.
The service life of the filter (Disposable hepa Filter )depends on its own advantages and disadvantages, such as filter material, filter surface product, structure design, initial resistance, but also with the dust concentration in the air, the actual use of air volume, the setting of the final resistance and other factors.
To grasp the appropriate service cycle, it is necessary to understand the change of resistance, first of all, we must understand the following definition:
1. Rated initial resistance: initial resistance provided by filter sample, filter characteristic curve or filter test report at rated air volume.
2. Initial design resistance: filter resistance under the designed air volume of the system (should be provided by the air conditioning system designer).
3. Initial operation resistance: at the beginning of the system operation, the resistance of the filter, if there is no pressure measurement instrument, can only take the resistance under the designed air volume as the initial operation resistance (the actual operation of the wind
Special note: Low efficiency filter generally use coarse fiber filter material, fiber gap is large, too large
In this case, the hepa filter resistance is no longer increased, but the filtration efficiency is reduced to almost zero. Therefore, the final resistance value of the coarse effect filter should be strictly controlled!
Several factors should be considered to determine the final resistance. The final resistance is low, the service life is short, the long-term replacement cost (filter cost, labor cost, and waste treatment cost) is high, but the operation energy consumption is low, so each filter should have the most economical final resistance value.
The dirtier the filter, the faster the resistance increases. The high final resistance does not mean that the filter life will be extended, the high resistance will make the air volume of the air conditioning system sharply. High final resistance is undesirable.
Customer complaints about the short service life of filters are mainly caused by three reasons
a, the filter material area is too small or the unit dust capacity is too small; b. The filtration efficiency of the pre-filter is low;
C. Users have high expectations on the service life of filters.