Replacement Cycle of Air Filter

Air filter is the core equipment of air conditioning purification system. The resistance of filter to air is formed. With the increase of filter dust, the resistance of filter will increase. When the filter accumulates too much dust and the resistance is too high, the air flow through the filter will be reduced, or the filter will be partially penetrated. Therefore, when the resistance of the filter increases to a specified value, the filter will be discarded. Therefore, the use of filters, to grasp the appropriate use cycle. When the filter is not damaged, the service life is usually determined by resistance.

The service life of the filter depends not only on its own advantages and disadvantages, such as filter material, filter area, structure design, initial resistance, but also on the dust concentration in the air, the actual air volume used, the setting of final resistance and other factors.

To grasp the suitable service life, we must understand the change of resistance. First of all, we must understand the following definitions:

3. Initial resistance of operation: At the beginning of system operation, the resistance of filter, if there is no pressure measuring instrument, can only take the resistance under the designed air volume as the initial resistance of operation (the actual air volume can not be totally equal to the designed air volume);

In operation, the resistance of the filter should be checked regularly when it exceeds the initial resistance (resistance monitoring device should be installed in each filter section) to decide when to replace the filter. The filter replacement cycle is shown in the table below (for reference only):

*Specially: Low efficiency filters generally use crude fiber filter material, the gap between fibers is large, and excessive resistance may blow away the dust deposited on the filter. In this case, the resistance of the filter is no longer increased, but the filtration efficiency is reduced to almost zero, so the final resistance value of crude efficiency filters should be strictly controlled!

Several factors should be considered in determining the final resistance. Low final resistance, short service life, high long-term replacement costs (filter costs, labor costs, and waste disposal costs), but low energy consumption, so each filter should have the most economical final resistance value.

Recommended final resistance:

*The dirtier the filter, the faster the resistance increases. Excessive ultimate resistance does not mean that the service life of the filter will be prolonged. Excessive resistance will make the air volume of the air conditioning system decrease sharply. Excessive final resistance is not advisable.