ASHRAE 52.2: Filter testing was originated from America in 1930 (ASHVE and AFI code). It was then reviewed and modified in 1967 and 1968. ASRHAE collaborated with American National Standard Institude (ANSI) in 1992 to create ASHRAE-ANSI 52.1. Finally updated to ASHRAE 52.2 in 2007.
EUROVENT 4/4 and 4/5: Eurovent 4/5 was established in 1974 by modifying existing ASHRAE 52-68 to suit the applications in Europe. Eurovent 4/5 is catered for primary and secondary filter while Eurovent 4/4 is catered for high efficiency filters
EN 779: It was the first European’s Air filter test method in 1993, built on the foundations of Eurovent 4/5. This standard was modified later in 2002 and 2012. Only covers primary and secondary filters.
EN 1882: It is the improvisation from Eurovent 4/4 in 1998. This standard was modified only once in 2010. It covers high efficiency filters (E10 and above).
AIR FILTERS and EFFICIENCY CLASSIFICATION
| CLASSIFICATION | Arrestance or Dust Spot Efficiency | US ASHRAE 52.2 | European Union EN779 Class | Typical Controlled Contaminant | Application | |
|---|---|---|---|---|---|---|
| PRE Filter (G Class) | AFI | MERV 1 | G1 | Am | Particle bigger than 10.0µm （Pollen） （Spanish moss） （Dust mites） （Sanding dust） （Spray paint dust） （Textile fibers） | Gross filter, domestic and commercial |
| AFI 65%-70% | MERV 2 | G2 | 65%≦Am | |||
| AFI 70%-75% | MERV 3 | |||||
| AFI 75%-80% | MERV 4 | |||||
| AFI 80%-85% | MERV 5 | G3 | 80%≦Am | Particle size within 3.0µm-10.0µm (Mold） (Spores） (Hair spray） (Cement dust） (Snuff） (Powdered milk） | Commercial, industrial, paint shop |
|
| AFI 85%-90% | MERV 6 | |||||
| NBS 25%-30% | MERV 7 | G4 | 90%≦Am | |||
| NBS 30%-35% | MERV 8 | |||||
| MEDIUM Filter (F Class) | NBS 40%-45% | MERV 9 | F5 | 40%≦Em | Particle Size within 1.0µm-3.0µm (Lead dust） (Milled flour） (Coal dust） (Auto emissions） (Nebulizer drop） (Welding fumes） | IAQ concerned commercial & industrial, medical |
| NBS 50%-55% | MERV 10 | |||||
| NBS 60%-65% | MERV 11 | F6 | 60%≦Em | |||
| NBS 70%-75% | MERV 12 | |||||
| NBS 80%-85% | MERV 13 | F7 | 80%≦Em | Particle size within 0.3µm-1.0µm (All bacteria） (cooking oil） (Most smoke） (Copier toner） (Most face powder） (Most paint pigments） | IAQ concerned commercial, industrial, medical, food etc |
|
| NBS 90%-95% | MERV 14 | F8 | 90%≦Em | |||
| NBS>95% | MERV 15 | F9 | 95%≦Em | |||
| MERV 16 | ||||||
| HEPA Filter (H Class) | ≧95% at 0.3µm | H10 | ≧85% at MPPS | Particle size bigger than 0.3µm (Virus [unattached]） (Carbon dust） (Sea salt） (All combustion smoke） (Radon progeny） | All types of cleanrooms | |
| ≧98% at 0.3µm | H11 | ≧95% at MPPS | ||||
| ≧99.97% at 0.3µm | TYPE A | |||||
| ≧99.99% at 0.3µm | TYPE C | H12 | ≧99.5% at MPPS | |||
| ≧99.995% at 0.3µm | H13 | ≧99.95% at MPPS | ||||
| ≧99.999% at 0.3µm | TYPE D | H14 | ≧99.995% at MPPS | |||
| ULPA Filter (U Class) | ≧99.9995% at 0.12µm | TYPE F | H15 | ≧99.9995% at MPPS | Particle size bigger than 0.12µm | super cleanroom |
| ≧99.99995% at 0.12µm | H16 | ≧99.99995% at MPPS | ||||
| ≧99.999995% at 0.12µm | H17 | ≧99.999995% at MPPS | ||||
1. AFI : American Filter Institute
2. NBS : National Bureau of Standards
3. ASHRAE : American Society of Heating Refrigerating & Air-conditioning Engineers
4. MERV : Minimum Efficiency Reporting Value
5. MPPS : Most Penetrating Particle Size
6. HEPA : High Efficiency Particulate Air Filter
7. ULPA : Ultra Low Penetration Air Filter
8. Am : Average Arrestance Efficiency for Coarse Filters
9. Em : Average Efficiency for Fine Filters
10. IEST : Institute of Environmental Sciences and Technology