The resistance of a new air filter when it is first used is the initial resistance, relatively speaking, the resistance of an air filter when it is scrapped (at the time of life) is the final resistance.
Like the primary effect filter and the medium effect filter their final resistance is twice the initial resistance. The final resistance of the high efficiency filter is two to three times the initial resistance. In many air conditioning equipment, the initial effect filter or medium effect filter is used for pre-filtration, and the efficient end filter is used.
In this way, in order to better protect the high efficiency filter, the initial effect filter first filters out large particles of dust, reduces the amount of dust on the high efficiency filter, and extends the service life.
Filter dust increases resistance, when the resistance reaches the final resistance, too much resistance will make the air filter has captured flying dust flying to form secondary pollution, in order to avoid the occurrence of this dangerous thing, the filter should be replaced in time when the final resistance reaches the new filter.
Air filter general manufacturers recommend 3-6 months to replace once, the specific time also depends on your frequency of use and use of the environment, some environments with high frequency of use of the work area filter final resistance may be reached in a month, that a month to replace a new filter.