Criteria for Judging the Replacement of High-Efficiency Filters (General for Clean Rooms, Simple and Direct)
There is no need to memorize the years. Instead, focus on checking the pressure difference, leak detection, cleanliness, and appearance. Any one of these conditions being met requires replacement.
1. The most standard: Check the pressure difference (most commonly used and most accurate)
Record the initial resistance (the pressure difference after the new filter is installed and stabilized)
When the final resistance ≥ 2 times the initial resistance → Replace immediately
Example: The initial pressure difference is 100 Pa, and it should be replaced when it reaches 200 Pa
This standard is strictly followed in DOP supply air outlets, liquid tanks, and GMP workshops.
An increase in pressure = accumulation of dust and blockage, decreased air volume, and deteriorated cleanliness
2. Insufficient leak detection (priority for DOP supply air outlets)
Use PAO/DOP leak detection scanning:
Filter body leakage, frame sealing leakage, liquid tank sealing failure
Insufficient leak detection → Replace immediately, cannot continue to use
3. Exceeding cleanliness / dust particle standards
Daily inspection in the workshop:
Suspension particles, microorganisms exceed standards
After excluding problems with the fan, duct, and return air, it is the failure of the high-efficiency filter
4. Abnormal appearance and operating conditions
Filter material damage, blackening, mold growth, moisture absorption
Significantly reduced air volume, weak air outflow from the outlet
Excessive dust in the workshop, failure of the pre-filter, and rapid contamination of the high-efficiency filter
In such cases, replace immediately.
5. Time reference (bottom-line standard)
Ordinary clean rooms: 1-2 years
GMP pharmaceutical / operating room: It is recommended to replace every 1 year (mandatory)
For workshops with large dust and frequent opening: 6-12 months