The initial resistance of the HEPA filter refers to the air circulation resistance of the newly-made filter under the rated air volume state. When the air filter runs under a certain air volume, its circulation resistance increases with the increase of the dust accumulation. Generally, when the dust accumulation reaches a certain value, the resistance increases faster. At this time, the filter should be replaced or cleaned. Ensure the economic operation of the purification air conditioning system. Generally speaking, the initial resistance of the high-efficiency filter is about 150-220PA.
The resistance of the HEPA filter is called the "initial resistance", and the resistance value corresponding to the scrapped filter is called the "final resistance". When designing, a representative resistance value is required. This resistance value is called "design resistance". The general method is to take the average of the initial resistance and the final resistance.
In most cases, the final resistance of the HEPA filter is 2 to 4 times the initial resistance. Table 3-1 gives some recommended final resistance. When the filter reaches the final resistance, it means that the filter must be replaced, which can be determined by installing a resistance monitoring device in each filter section, such as using a differential pressure gauge. Recommended final resistance value of air filter Filter efficiency specification recommended final resistance/Pa" coarse efficiency 100~200 medium efficiency 250~300 high medium efficiency 300~400 sub-efficient 400~450 high efficiency 400~600
