Replacement cycle for high-efficiency filters (HEPA)
Regular cleanroom (D grade / C grade): 1 to 3 years
Critical clean areas (B grade / A grade): 1 to 2 years
High environmental dust and poor front-end filtration: 6 to 12 months
The 3 decisive factors that truly determine whether to replace (more accurate than time)
Resistance reaches the final resistance of the new filter resistance × 2 or reaches the manufacturer’s specified final resistance (generally 400–450 Pa) → Must replace.
Leak detection failure PAO leak detection test: Dust is emitted upstream and leakage is detected downstream → Must replace.
When the service life reaches the upper limit, even if the resistance is not high and it does not look dirty, it is generally not recommended to exceed 3 years (filter paper will age, sealant will crack, and sealing will fail).
Here is a concise version that can be directly written into the record
Primary efficiency: 1–3 months
Intermediate efficiency: 3–6 months
High efficiency: 1–3 years (judged by resistance + leak detection + service life in combination)