Determination of filtration performance
The standard defines the requirements for particle filters and describes both the methods and the test bench for measuring filter performance.
This European standard applies to air filters with an initial efficiency of less than 98% for 0.4-micron particles. Filters must be tested with air flow rates between 0.24 m³/s (850 m³/h) and 1.5 m³/s (5400 m³/h).
This new legislation was approved in March 2012 and implemented in Italy in June 2012. It introduces a significant change for fine filters (F7, F8 and F9) which will have to comply with a new parameter: minimum efficiency (ME).
One effect of this new regulation will be the reclassification of almost all the old-concept synthetic fibre filters. The synthetic fibre is electrostatically charged during processing, which improves the initial performance of the product in terms of efficiency. After a short time, however, the electrostatic charge diminishes, and efficiency consequently decreases.
To overcome this, synthetic fibre producers are developing new-concept baffles to meet the new regulations in terms of efficiency. Unlike synthetic fibre, fibreglass is not affected by the loss of electrostatic charge and maintains efficiency throughout its life cycle, ensuring performance that complies with the regulatory limits for the entire operating life of the filter.
Following the introduction of this standard, the old "Fine" F5 and F6 filters are now classified as "Medium", i.e. M5 and M6.
| Group | Class | Final pressure drops (Pa) | Average arrestance (AA) with synthetic powder % | Average efficiency (AE) on 0.4 µm particles % | Minimum efficiency* on 0.4 µm particles % |
|---|---|---|---|---|---|
| Coarse | G1 | 250 | 50 ≤ Am < 65 | – | – |
| G2 | 250 | 65 ≤ Am < 80 | – | – | |
| G3 | 250 | 80 ≤ Am < 90 | – | – | |
| G4 | 250 | 90 ≤ Am | – | – | |
| Medium | M5 | 450 | – | 40 ≤ Em < 60 | – |
| M6 | 450 | – | 60 ≤ Em < 80 | – | |
| Fine | F7 | 450 | – | 80 ≤ Em < 90 | 35 |
| F8 | 450 | – | 90 ≤ Em < 95 | 55 | |
| F9 | 450 | – | 95 ≤ Em | 70 | |
| * minimum efficiency is è the lowest efficiency among the following: initial efficiency, discharge efficiency and the lowest efficiency found during the dust load test | |||||
PD 02692170281/1996
