The core conclusion on the replacement cycle of air purifier filters: Under regular usage scenarios, HEPA filters should be replaced every 6–12 months, and activated carbon filters every 3–6 months—specific timelines can be adjusted based on the usage environment and filter condition.
I.Core Influencing Factors
1.Usage environment: In scenarios with heavy smog, high dust levels, pet ownership, or smoking, the filter load doubles, so the replacement cycle should be halved (HEPA filters: 3–6 months; activated carbon filters: 1–3 months).
2.Usage frequency: If the purifier runs for over 8 hours a day, the cycle is shortened by about 30% compared to occasional use. For long-term inactivity (more than 3 months), activated carbon filters may fail due to adsorption saturation—replace them when restarting.
3.Filter type:
HEPA filters (including H13/H14 grades): Made of glass fiber or synthetic fiber, they cannot be restored by cleaning after saturation and must be replaced directly.
Activated carbon filters (including honeycomb carbon, granular carbon): Adsorb gaseous pollutants like odors and formaldehyde, and easily saturate. Saturated filters may release pollutants, so timely replacement is necessary.
Composite filters (integrated HEPA + activated carbon): Follow the "first-to-fail" principle, usually requiring replacement every 6 months or so.
II.Practical Judgment Methods
1.Check device prompts: Most air purifiers are equipped with a filter life indicator light—replace the filter when the light turns on or flashes.
2.Trust usage experience: If the purification speed slows significantly, there is an odor from the air outlet, or the indoor PM2.5 value is difficult to drop to an excellent level, the filter is likely ineffective.
3.Visual inspection: Replace the HEPA filter if it has heavy surface dust that cannot be removed by tapping; replace the activated carbon filter if its color darkens or it feels damp.
