Filter Classes
European Normalisation standards recognise the following filter classes:
| Usage | Class | Performance | Performance test | Particulate size approaching 100% retention |
Test Standard |
|---|---|---|---|---|---|
| Primary filters | G1 | 65% | Average value | >5 µm | BS EN779 |
| G2 | 65–80% | Average value | >5 µm | BS EN779 | |
| G3 | 80–90% | Average value | >5 µm | BS EN779 | |
| G4 | 90%– | Average value | >5 µm | BS EN779 | |
| Secondary filters | F5 | 40–60% | Average value | >5 µm | BS EN779 |
| F6 | 60–80% | Average value | >2 µm | BS EN779 | |
| F7 | 80–90% | Average value | >2 µm | BS EN779 | |
| F8 | 90–95% | Average value | >1 µm | BS EN779 | |
| F9 | 95%– | Average value | >1 µm | BS EN779 | |
| Semi Hepa | H10 | 85% | Minimum value | >1 µm | BS EN1822 |
| H11 | 95% | Minimum value | >0.5 µm | BS EN1822 | |
| H12 | 99.5% | Minimum value | >0.5 µm | BS EN1822 | |
| Hepa | H13 | 99.95% | Minimum value | >0.3 µm | BS EN1822 |
| H14 | 99.995% | Minimum value | >0.3 µm | BS EN1822 |
Read more about this topic: Air Filter
Famous quotes containing the word classes:
“We deny your internationalism, because it is a luxury which only the upper classes can afford; the working people are hopelessly bound to their native shores.”
—Benito Mussolini (1883–1945)