Which filter class suits my ventilation set-up?

The filters in your MVHR system play an important role in cleaning the air. There are different filter classes to choose from. Each class has a different filtration efficiency. Where one is better for coarse particles, another is better for medium or fine particles. We are happy to explain what the different filter classes mean so you can choose the best filter for your situation and indoor climate.

Luchtfilters_WTW filter_schap

What is the difference between the different filter classes?

Each type of MVHR filter has its own filter class. The different filter classes indicate the extent to which the filters allow (fine) dust to pass through the medium. A higher filter class automatically means that more dust is stopped.

Filters can be classified as Coarse (G3 and G4), Medium (M5 and M6) and Fine (F7).

Coarse filters

Coarse filters can be divided into filter class G3 and G4. These filters have a relatively low filter class and are used for air extraction. These filters protect both the indoor air and the MVHR unit from coarse dust particles, insects, sand and hair. Filter class G3 is mainly used in moderately polluted environments, while filter class G4 is more likely to be used in a highly polluted environment such as an industrial area.

Medium filters

Filter classes M5 and M6 fall under medium filters. These filters have a higher filter class than the coarse filters and are thus suitable for blocking dust particles that cannot be detected by the naked eye. Filter class M5 provides good filtration for moderate amounts of dust and dirt, such as: sand, insects, hair, dust particles, ... Filter class M6 protects even small particles such as spores, pollen and mold.

Fine dust filter

The fine dust filter with filter class F7 is used for air supply and offers the highest filtration degree. These filters can filter small particles from the air such as: pollen, carbon black, fine dust, dust mites, pet dander and some bacteria and viruses. F7 filters are often used in environments with high levels of air pollution.


The G3, G4 and M5 filters are suitable for extracting polluted air to the outside. These filters protect the MVHR unit from pollution, giving it a longer life. For the supply of clean air, the M6 and F7 filters are the most suitable. This is because they stop the most pollution, so the air, which is blown into the house or building, is optimal.

No matter which filter class you use, it is important to change your MVHR system's filters regularly to keep the air you breathe clean. Changing filters is a relatively simple job.

Would you rather have this done by a technician? If so, you can always have maintenance performed on your MVHR system. Filters should be ordered in advance or can be ordered and replaced by the technician. You can order them here. It is also important to follow the manufacturer's recommendations for changing filters, as this may vary by specific model.

More about Intovent
Filters_Zehnder_ComfoAir E 300_ComfoAir E 400 Filters_Orcon_HRC 300_HRC 400_EcoMax_MaxComfort Filters_Itho Daalderop_HRU ECO 350 Filters_Brink_Flair 300_Flair 400 Filters_Duco_DucoBox Energy Comfort_DucoBox Energy Premium