AboutHEPA filters, different countries or regions have its different classifications according to their standards. Similarly, the requirements for cleanliness vary from industry to industry.

HEPA Filters’ features :

1. Primary filter : it mainly used as a pre-filter for the fresh air inlet of the air conditioning system, intercepting the large particle from atmosphere. Filtration efficiency is subject to filtration ≥5.0um particles.
2. Medium filter : it can be used as the final filter for general air conditioning systems and as a pre-filter for high efficiency filters in air conditioning systems. Mainly used to intercept 1-10um suspended particles, the efficiency is subject to filtration ≥1um particles.
3. High-medium filter : it can be used as a system end filter for general purification and as an intermediate filter for high efficiency filters. Mainly intercept 1-5um particles, the efficiency is subject to filtration ≥1um particles.
4. Sub-hepa filter : it mainly used as a clean room end filter, as a pre-filter for high-efficiency filters and a final filter for fresh air systems. Filtration efficiency is subject to filtration ≥0.3um particles.
5. Hepa filter : it used as the end filtration of clean room to ensure all cleanliness requirement. Filtration efficiency is subject to filtration ≤0.3um particles.

According to European standards, Primary filter is divided into 3 levels,G1,G2,G3; Medium filter is divided into 3 levels,G4,F5,F6; High-medium filter is divided into 2 levels,F7,F8; Sub-hepa filter is divided into 3 levels, F9,H10,H11; Hepa filter is divided into 3 levels, H12,H13,H14.