I. Chinese Standards
Classification System
According to the national standard “High Efficiency Air Filters” GB/T 13554-2008, it is classified into the following categories:
High Efficiency Particulate Air (HEPA) Filter: Filtration efficiency ≥ 99.9% (sodium flame method or oil mist method)
Ultra High Efficiency Particulate Air (ULPA) Filter: Filtration efficiency ≥ 99.999% (for particles ≥ 0.1 μm)
Grade classification: Class A (efficiency ≥ 99.9% at rated air volume), Class B (≥ 99.99%), Class C (≥ 99.999%), Class D (≥ 99.999% and for particles ≥ 0.1 μm)
Test methods
The sodium flame method or oil mist method is the basis for efficiency testing, and the test standard refers to GB/T 6165-2008.
II. European Standards
EN 1822 Standard
It is applicable to sub-efficient to ultra-efficient filters, and the classification is as follows:
H13: Filtration efficiency ≥ 99.95% (for 0.3 μm particles)
H14: Filtration efficiency ≥ 99.995% (for ≥ 0.3 μm particles)
U15 – U17: Ultra-efficient filters, efficiency ≥ 99.9995% and above
EN 779 standard
Applicable to coarse to medium efficiency filters, but for high efficiency and above, refer to EN 1822.
III. American Standards
ASHRAE 52.2 Standard
Applicable to coarse to sub-efficient filters, classified based on size efficiency:
High-efficiency filters: Corresponding to H13 to H14 grades, with efficiency ≥ 99.95% to 99.995%
IEST-RP-CC001 standard
Specifically designed for high-efficiency and ultra-high-efficiency filters, with performance requirements similar to EN 1822.
IV. Key Performance Parameters
Material Requirements
Tensile strength of filter paper: longitudinal ≥ 0.7 kN/m, transverse ≥ 0.5 kN/m
Frame material: cold-rolled steel plate (1.0 – 2.0 mm), aluminum alloy (1.5 – 2.0 mm), stainless steel (1.0 – 2.0 mm)
Production environment
The assembly workshop for high-efficiency filters needs to meet the air cleanliness level of 8.
V. Application Scenarios
H13/H14: Biological laboratories, hospital clean rooms, semiconductor factories
U15-U17: Advanced electronic manufacturing, nuclear industry, and other high-precision environments
The above standards and grade classifications reflect the quantitative requirements for air filtration performance in different regions. In actual selection, a comprehensive assessment should be made based on specific application scenarios and testing standards.