The service life of high-efficiency filters is significantly influenced by factors such as environmental cleanliness, the performance of the pre-filtration system, and operating conditions, typically ranging from 6 months to 3 years. The specific duration should be determined based on the following scenarios:
I. Core Factors Affecting Service Life
Concentration of environmental pollutants
Highly polluted environments (such as chemical workshops and dusty workshops): There are many pollutants and large particles, and filters are prone to clogging. Their lifespan is usually 6 to 12 months.
Moderately polluted environments (such as ordinary laboratories and food workshops): The amount of dust is moderate, and the lifespan is approximately 1-2 years.
Low-pollution environments (such as medical operating rooms and electronic clean rooms): There is less daily dust and strict pre-filtration, with a lifespan of up to 2-3 years.
The effectiveness of the pre-filtering system
Primary and medium-efficiency filters serve as the “protective layer” for high-efficiency filters.
If the pre-filter is replaced regularly (1-2 months for the primary filter and 3-6 months for the medium filter), it can intercept over 80% of large particle pollutants, and the service life of the high-efficiency filter can be extended by 30% to 50%.
If the pre-filter fails (such as being overdue for replacement or damaged), the high-efficiency filter will directly bear the filtration load, and its service life may be shortened to half of the original.
Operating conditions
Excessively high wind speed (more than 1.5 times the design value): The airflow impact will accelerate the aging of the filter material, and at the same time, it will cause an increase in the penetration rate of pollutants and shorten their lifespan.
High environmental humidity (such as during the rainy season in the south or condensation in clean rooms): Filter materials are prone to moisture and mold growth. Especially for non-moisture-proof filters (such as those made of ordinary glass fiber), their lifespan may be reduced by one-third.
Ii. Key Indicators for Judging Replacement (Rather than Fixed Time)
Resistance variation
When the operating resistance of the filter reaches twice the initial resistance (or the upper limit set by the manufacturer, such as 300Pa), it must be replaced – excessive resistance will lead to a decrease in air volume, an increase in energy consumption, and the filter material is approaching the clogging limit.
Example: The initial resistance of the new filter is 120Pa. If the resistance rises above 240Pa during operation, a replacement plan is required.
Attenuation of filtration efficiency
Even if the resistance has not reached the upper limit, if the DOP/PAO leak detection test shows that the leakage rate exceeds 0.01% (Class 5 and above cleanroom standards), or the filtration efficiency drops below 80% of the design value, immediate replacement is required (the filter material may be damaged or aged).
Emergency
In the event of environmental pollution accidents (such as dust leakage, chemical explosion), Pollutants may penetrate the filter material or damage the structure. The machine needs to be shut down for inspection and replaced directly.
If the filter gets damp or corroded (such as coming into contact with oil stains, acidic, or alkaline gases), the structure of the filter material will be damaged. Even if it has been in use for a short time, it must be replaced.
Iii. Practical Suggestions for Extending Life
Strictly maintain the pre-filtering system to avoid the situation where “small filters save money while large ones accelerate replacement”.
Regularly clean the surrounding environment of the filter to reduce the accumulation of dust being carried into the filter material by the airflow.
Keep the operating wind speed within the design range (generally 0.3-0.5m/s) and avoid overloading operation.
Summary
High-efficiency filters do not have an “absolutely fixed” lifespan. A comprehensive judgment should be made based on the usage environment, resistance monitoring, and leak detection results. The core principle is: do not exceed the service life, do not delay based on experience, and use data and performance as the basis for replacement. Proper maintenance can maximize its service life while ensuring the stability of a clean environment.
