Filter class G4, M6, F9 and so on. For those who have a MVHR system, these terms are probably not unknown. Something has changed since August 2018: the filter standard EN779 has been replaced by ISO16890. This means that the aforementioned terms will make way for new, more specific names. In this blog we would like to explain the differences.
Differences between EN779:2012 and ISO16890 regulations
The big difference between EN779 (old) and ISO16890 (new) is the scope of the test. Previously it was only tested how many 0.4 micrometer dust particles were retained by the filter. Not very useful, as particulate matter occurs in different sizes. The new ISO16890 filter standard was created to give you a better picture of a filter's performance. All MVHR filters from Ventilationland have been tested according to the ISO16890 quality mark and this filter standard is international. So from now on it is much easier to compare filters of different international brands.
New values
In the new ISO16890 regulations, the following values must be given for each filter:
- ISO Coarse - percentage of coarse dust retained by the filter
- ISO ePM1 - percentage of particulate matter ( < 1 µm ) retained by the filter
- ISO ePM2,5 - percentage of particulate matter ( < 2,5 µm ) retained by the filter
- ISO ePM10 - percentage of particulate matter ( < 10 µm ) retained by the filter
Instead of categorising a filter under a certain filter class, it now specifies in detail what percentage of which particles are retained by the filter. This means that no fixed designations are used anymore, but that each class is given a certain percentage. If a filter scores at least 50% on a certain ePM, then the corresponding designation can be used to indicate under which 'filter class' this filter falls.
Compare filter classes
The quality and filter class of a filter is not always clear, and often the old EN779 standard is still used. Therefore we have an overview of the different filter classes and the typical values for such a filter in the new IS16890 standard. Please note: this is an indication and may vary per brand.
| Filter class |
ISO Coarse |
ISO ePM10 |
ISO ePM2,5 |
ISO ePM1 |
| G3 |
> 45 % |
- |
- |
- |
| G4 |
> 90 % |
- |
- |
- |
| M5 |
> 95 % |
> 50 % |
- |
- |
| M6 |
> 95 % |
> 60 % |
50 - 60 % |
- |
| F7 |
> 95 % |
> 85 % |
65 - 80 % |
50 - 65 % |
| F8 |
> 95 % |
> 90 % |
> 80 % |
65 - 80 % |
| F9 |
> 95 % |
> 95 % |
> 95 % |
> 80 % |
Purchase WTW filters
Are you looking for new filters for your MVHR? Then take a look at our wide range of MVHR filters. It is recommended to replace the MVHR filters on a regular basis, preferably once every six months. View all MVHR filters by brand:
