‌Primary Air Filter ‌
The primary air filter serves as the first line of defense in an air filtration system, primarily designed to filter large particles such as dust, hair, and fibers larger than 5 microns. Its key role is to protect downstream medium or high-efficiency filters, thereby extending the overall lifespan of the equipment.

‌Key Features and Materials‌

• ‌Filtration Accuracy‌: Targets particles larger than 5μm, including dust, dander, and pet hair.
• ‌Common Materials‌: Non-woven fabric, nylon mesh, or metal mesh; some washable types (e.g., metal or synthetic fiber) can be reused after cleaning.
• ‌Applications‌: Widely used in household air conditioners, air purifiers, and industrial ventilation systems for preliminary filtration.

‌Maintenance and Replacement Recommendations‌

• ‌Cleaning Method‌: Washable screens can be rinsed with water or cleaned with a soft brush; allow to dry before reinstalling.
• ‌Replacement Cycle‌:
  • ‌Residential environments‌: Replace every 3–6 months.
  • ‌High-dust environments (e.g., industrial areas)‌: Replace every 1–3 months.
• ‌Replacement Criteria‌: Replace immediately if the screen is damaged, deformed, or shows significant performance degradation after cleaning.

‌Difference from Other Filters‌

The primary filter screen works in tandem with HEPA filters: the former captures large particles, while the latter filters fine particles as small as 0.3 microns (e.g., PM2.5, pollen). Most air purifiers use a multi-layer filter combination of "primary + HEPA + activated carbon" for comprehensive air purification.