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Air filter initial resistance and final resistance value

2018-12-19

In the air filter resistance and the initial filter resistance comparison, we can more intuitively understand the relevant parameters of various P air filters, which is more convincing for us in the selection of air filters. Let us refer to air filtration together. Resistance and initial filter resistance!

Air filter resistance

The air filter forms a resistance to the air flow. The air filter is dusty and the resistance is added. When the resistance increases to a certain resistance value, the air filter is scrapped. The resistance of the new air filter is called “initial resistance”; the resistance value corresponding to the scrap of the air filter is called “final resistance”;

At design time, a representative resistance value is often required to calculate the air volume of the system. This resistance is called “design resistance” and is the average of the initial resistance and the final resistance.

The choice of final resistance is directly related to the service life and air volume of the air filter. Usually, the choice of final resistance is a matter for engineering designers. An experienced engineer can change the final resistance value of the original design based on the site conditions. Some designers will forget to inform the user of the final resistance value he selected; sometimes the user will change other models of air filters or other suppliers, then the engineer has to determine the final resistance value.

The final resistance is 2 to 4 times the initial resistance, the final resistance of G3 (primary filter) is 100 to 200 PA, G4 is 150 to 250 PA, F5 to F6 (medium effect) 250 to 300 PA, F7 to F8 (high and medium efficiency). 300 ~ 400PA, F9 ~ H11 (sub-efficient) 400 ~ 450, efficient and very efficient 400 ~ 600PA;

The dirtier the air filter, the greater the resistance. Too high a final resistance value does not mean that the service life of the air filter is significantly improved, but it will cause a sharp drop in the air conditioning system. Therefore, it is not necessary to set the final resistance value too high. Low-efficiency air filters often use coarse fiber filters with a diameter of ≥10 mm. Because of the large pore size between the fibers, excessive resistance may cause the ash on the air filter to blow away. At this time, the resistance is no longer increased, but the filtration efficiency is reduced to zero. Therefore, it is necessary to severely limit the final resistance value of the air filter below G4. Resistance monitoring Each filter section should be equipped with a resistance monitoring device. The final resistance depends on the meter to determine, not just the operator's feelings.