The maintenance and replacement cycle of the pleated high-efficiency filter (usually referring to the pleated high-efficiency air filter, which uses glass fiber filter paper as the filter material and aluminum foil or paper as the separator) has no fixed standard. It needs to be comprehensively judged based on the usage scenario, pollution level, equipment parameters and compliance requirements. The core basis is the degree of filtration efficiency attenuation and resistance change. The following is the specific analysis:
I. Core Judgment Indicators: Resistance and Filtration Efficiency
The core logic of maintenance and replacement is that when the filter resistance rises to the “final resistance” or the filtration efficiency drops to the point where it cannot meet the cleanliness requirements, it must be replaced. These two indicators need to be confirmed through regular monitoring.
| Indicator type | Definitions and Standards | Monitoring method |
| Resistance monitoring |
Initial resistance: The resistance of a new filter at its rated air volume (provided by the manufacturer, typically 150-250Pa). Final resistance: The resistance when the filter can no longer be used, generally set at 2 to 3 times the initial resistance (such as 300-750Pa). |
Read through the differential pressure gauge that comes with the air handling unit/air conditioning unit; Regularly measure the pressure difference before and after the filter with a professional micromanometer. |
| Efficiency monitoring | The filtration efficiency of the filter for 0.3μm particles should be maintained at ≥99.97% (HEPA standard) or ≥99.999% (ULPA standard). |
1. Regular “particle counter testing” is conducted in the clean area. If the cleanliness does not meet the standards (such as the particle count exceeding the standard in Class 100 area), 2. Perform “scanning leak detection” on the filter (such as photometer scanning). Replace it when the filter material is found to be damaged or the frame is leaking. |
Ii. Reference for Regular Replacement Cycles (Classified by Scenarios)The pollution load varies greatly in different scenarios, and the replacement cycle can differ by several times. The following are the common empirical values in the industry (which need to be verified in combination with resistance/efficiency monitoring)
| Application scenarios | Degree of pollution | Regular replacement cycle | Key influencing factors |
| Biosafety Laboratory (P2/P3) | Medium to high | 1 to 3 years | Frequent handling of microorganisms leads to a large amount of aerosol contamination, so the monitoring interval needs to be shortened (such as measuring resistance once every three months). |
| Pharmaceutical clean area (GMP A/B grade) | In the | 2 to 4 years | It must comply with GMP standards. After replacement, cleanliness verification must be conducted again. If dust-containing drugs are produced, the production cycle may be shortened to 1 to 2 years. |
| Electronic cleanroom (Semiconductor/chip) | Low – medium | 3 to 5 years | The air cleanliness base is high (such as Class 10), the pollution load is low, but the efficiency requirement is extremely strict. If there is a leakage, it needs to be replaced. |
| Hospital Operating Room (100 level / 1000 level) | In the | 2 to 3 years | Frequent surgeries and high personnel turnover require postoperative cleanliness tests. If there is a risk of infection, changes should be made in advance. |
| General laboratory/food clean area |
low |
4 to 6 years | When the pollution load is low and the resistance rises slowly, the monitoring interval can be extended (for example, measuring the resistance once every six months). |
Iii. Maintenance Points: Key Measures for Extending the Service Life of Filters
The core of maintenance is to prevent high-efficiency filters from being contaminated prematurely, which can be achieved through “pre-filtration” and “regular inspection”
1. Maintenance of the pre-filtration system (Core protective measures)
The lifespan of the high-efficiency filter directly depends on the interception effect of the pre-filter and should be maintained in accordance with the following requirements:
Primary filter (G4 grade) : Intercepts large particles of dust (≥5μm). Clean/replace once every 1-3 months (for washable non-woven fabric materials, wash and dry for reuse; for paper materials, replace directly).
Medium-efficiency filter (F8 grade) : Intercepts medium particles (≥1μm), and needs to be replaced every 3 to 6 months (not washable, requires overall replacement).
If the pre-filter is not maintained in time, a large amount of dust will directly clog the high-efficiency filter, causing its resistance to increase sharply and its service life to be shortened by more than 50%.
2. Regularly inspect the filter body
Visual inspection: Every month, visually check whether the filter frame is well sealed (no air leakage, no deformation), and whether there is any damage or mold on the surface of the filter material (special attention should be paid in damp environments).
Sealing performance inspection: Every 1-2 years, the sealing condition of the filter and the frame should be tested by the “aerosol scanning method” (such as using PAO aerosol and photometer). If the leakage rate exceeds 0.01%, resealing or replacement is required.
Air volume balance check: Every six months, check whether the air volume in the clean area is stable (such as within ±10% of the rated air volume). If the air volume drops sharply, it may be due to filter blockage or fan failure, and timely investigation is required.
Iv. Special Circumstances: Scenarios that require immediate replacement
Even if the regular cycle has not been reached, the filter must be replaced immediately when the following situations occur
The resistance exceeds the final resistance (for example, the manufacturer stipulates that the final resistance is 400Pa, but the actual detection reaches 450Pa).
The scanning leak detection found that the filter material was damaged or the frame was leaking (which could not be repaired by sealing).
The particle count in the clean area has been persistently exceeding the standard (excluding other factors such as fresh air pollution and personnel operation).
Major pollution incidents occur (such as microbial leakage in biological laboratories or material contamination in pharmaceutical workshops).
V. Compliance Requirements (Key Industries)
Pharmaceutical industry (GMP) : It is necessary to record the purchase, installation, replacement dates and test data of the filters. After replacement, “cleanliness revalidation” (such as particle count and sedimentation bacteria testing) should be conducted to ensure compliance with the requirements of GMP Appendix 1.
Biosafety Laboratory (GB 19489) : The replacement of high-efficiency filters must be carried out by professionals. After replacement, the filters should be “disinfected and sealed” (such as being fumigated with formaldehyde and then sealed) to prevent the leakage of harmful microorganisms.
Electronics industry (ISO 14644) : After replacement, “cleanroom performance testing” is required, including verification of air volume, air velocity, and cleanliness grade, to ensure compliance with production process requirements.
Resumen
The replacement cycle of the separator high-efficiency filter is based on “resistance and efficiency” as the core judgment criteria. In conventional scenarios, it ranges from 1 to 6 years. The key to maintenance is to ensure regular replacement and daily monitoring of the pre-filtration system. It is recommended to establish a “filter maintenance file” to record the resistance and efficiency data of each test. Through trend analysis, the replacement time can be predicted in advance to avoid the impact on production or experimental safety due to sudden failure.
The core of maintenance is to prevent high-efficiency filters from being contaminated prematurely, which can be achieved through “pre-filtration” and “regular inspection”
1. Maintenance of the pre-filtration system (Core protective measures)
The lifespan of the high-efficiency filter directly depends on the interception effect of the pre-filter and should be maintained in accordance with the following requirements:
Primary filter (G4 grade) : Intercepts large particles of dust (≥5μm). Clean/replace once every 1-3 months (for washable non-woven fabric materials, wash and dry for reuse; for paper materials, replace directly).
Medium-efficiency filter (F8 grade) : Intercepts medium particles (≥1μm), and needs to be replaced every 3 to 6 months (not washable, requires overall replacement).
If the pre-filter is not maintained in time, a large amount of dust will directly clog the high-efficiency filter, causing its resistance to increase sharply and its service life to be shortened by more than 50%.
2. Regularly inspect the filter body
Visual inspection: Every month, visually check whether the filter frame is well sealed (no air leakage, no deformation), and whether there is any damage or mold on the surface of the filter material (special attention should be paid in damp environments).
Sealing performance inspection: Every 1-2 years, the sealing condition of the filter and the frame should be tested by the “aerosol scanning method” (such as using PAO aerosol and photometer). If the leakage rate exceeds 0.01%, resealing or replacement is required.
Air volume balance check: Every six months, check whether the air volume in the clean area is stable (such as within ±10% of the rated air volume). If the air volume drops sharply, it may be due to filter blockage or fan failure, and timely investigation is required.
Iv. Special Circumstances: Scenarios that require immediate replacement
Even if the regular cycle has not been reached, the filter must be replaced immediately when the following situations occur
The resistance exceeds the final resistance (for example, the manufacturer stipulates that the final resistance is 400Pa, but the actual detection reaches 450Pa).
The scanning leak detection found that the filter material was damaged or the frame was leaking (which could not be repaired by sealing).
The particle count in the clean area has been persistently exceeding the standard (excluding other factors such as fresh air pollution and personnel operation).
Major pollution incidents occur (such as microbial leakage in biological laboratories or material contamination in pharmaceutical workshops).
V. Compliance Requirements (Key Industries)
Pharmaceutical industry (GMP) : It is necessary to record the purchase, installation, replacement dates and test data of the filters. After replacement, “cleanliness revalidation” (such as particle count and sedimentation bacteria testing) should be conducted to ensure compliance with the requirements of GMP Appendix 1.
Biosafety Laboratory (GB 19489) : The replacement of high-efficiency filters must be carried out by professionals. After replacement, the filters should be “disinfected and sealed” (such as being fumigated with formaldehyde and then sealed) to prevent the leakage of harmful microorganisms.
Electronics industry (ISO 14644) : After replacement, “cleanroom performance testing” is required, including verification of air volume, air velocity, and cleanliness grade, to ensure compliance with production process requirements.
Resumen
The replacement cycle of the separator high-efficiency filter is based on “resistance and efficiency” as the core judgment criteria. In conventional scenarios, it ranges from 1 to 6 years. The key to maintenance is to ensure regular replacement and daily monitoring of the pre-filtration system. It is recommended to establish a “filter maintenance file” to record the resistance and efficiency data of each test. Through trend analysis, the replacement time can be predicted in advance to avoid the impact on production or experimental safety due to sudden failure.
