The filtration class indicates the filter’s ability to arrest dust particles of a given size.
For example, if we want to ensure complete removal of 2-micron sized particles from the air, which filter should we use?
We need to find 2 microns on the horizontal axis, which then extends to 100% filtration; the curve that guarantees this performance (formerly EU8) corresponds to the current F-8 class, therefore using an F-6 filter (formerly EU6), 2-micron particles would be arrested at a rate of 80%.
The tables below explain the filter efficiency classes to help technicians select the filter that offers the best solution in terms of efficiency, pressure drop, dust accumulation, and operating costs. Table 1 indicates the dust arrestance efficiency of each class for particles of different sizes. Table 2 shows how the dust is distributed in normal atmospheric air. Table 3 gives the gravimetric efficiency in weight, referring to a standard powder, of G1-G4 class filters. Table 4 indicates the opacimetric efficiency of M5-F9 class filters. Table 5 gives the efficiency of the absolute filters, using the maximum penetration method.
Purification efficiency % referring to the particle size to be filtered
| Particle size um | Class G2 | Class G4 | Class M5 | Class M6 | Class F7 | Class F8 | Class F9 |
| 0,2 | 60% | 79% | |||||
| 0,3 | 45% | 71% | 86% | ||||
| 0,4 | 3% | 8% | 21% | 56% | 77% | 90% | |
| 0,5 | 7% | 13% | 29% | 63% | 82% | 93% | |
| 0,6 | 10% | 24% | 36% | 68% | 85% | 95% | |
| 0,8 | 15% | 27% | 47% | 78% | 90% | 97% | |
| 1 | 22% | 35% | 55% | 84% | 92% | 99% | |
| 2 | 49% | 55% | 68% | 79% | 97% | 100% | 100% |
| 3 | 71% | 79% | 88% | 90% | 100% | ||
| 4 | 82% | 90% | 95% | 96% | |||
| 5 | 86% | 95% | 97% | 100% | |||
| 6 | 90% | 97% | 100% | ||||
| 8 | 94% | 99% | |||||
| 10 | 95% | 100% | |||||
| 20 | 100% |
Parameters of atmospheric air dust concentration
| Particle diameter |
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| inf. a 0,5 um |
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| 0.5 um – 1 um |
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| 1 um – 3 um |
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| 3 um – 5 um |
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| 5 um – 10 um |
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| 10 um – 20 um |
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Average fractional efficiency at 0.4 μm EN779
| Class M5 | Class M6 | Class F7 | Class F8 | Class F9 |
| 40-60% | 60-80% | 80-90% | 90-95% | > 95% |
Efficiency M.P.P.S. EN1822-1
| Class H10 | Class H11 | Class H12 | Class H13 | Class H14 |
| 85% | 95% | 99,5% | 99,95% | 99,995% |
Average gravimetric arrestance EN779
| Class G1 | Class G2 | Class G3 | Class G4 |
| < 65 % | 95-80% | 80-90% | > 90% |
Efficiency M.P.P.S. EN1822-1
| Class U15 | Class U16 | Class U17 |
| 99,9995 % | 99,99995% | 99,999995% |
PD 02692170281/1996
