In France, mechanical ventilation in homes is usually referred to as VMC – Ventilation Mécanique Contrôlée. Whether it is a simple flux or a double flux system, the performance of the installation depends strongly on one element that is often forgotten: the VMC filters.
Many online searches start with terms such as “filtre VMC” or “filtre VMC double flux”. But what should you really look at when you choose replacement filters for your VMC?
Why VMC filters are important
In a VMC simple flux, the system extracts stale air from bathrooms, toilets and the kitchen. Filters help protect the fan and ductwork from dust and grease. In a VMC double flux, there is also a heat exchanger and a supply air path: in that case, filters are crucial to protect both the heat exchanger and the indoor air quality in living rooms and bedrooms.
Good VMC filtration helps to:
- reduce dust and particles entering the home,
- protect the heat recovery core in double flux units,
- limit deposits of grease and dirt inside the ducts,
- keep airflows and fan energy consumption under control.
What to check before ordering a VMC filter
Before buying a new VMC filter, take a moment to check:
- Brand and model of the VMC (often indicated on the unit or in the user manual).
- Dimensions of the filter (width × height × thickness in mm).
- Filter type: filter mat, cassette filter, bag or pocket filter, etc.
- Filter performance, usually indicated according to EN or ISO standards (for example ePM1 or ePM2,5 according to ISO 16890).
For double flux systems, it is common to use a more efficient filter (e.g. ePM1) on the supply air side and a coarser filter on the exhaust air side. This combination protects people and equipment without creating unnecessary pressure drop.
Keeping VMC filters in good condition
The useful life of VMC filters depends on several factors: outdoor air quality, the location of the building (for example, near a busy road or in a quiet area), indoor dust and grease levels, and how many hours per day the system runs.
Instead of following a fixed replacement rule, it is generally advisable to:
- follow the maintenance instructions provided by the VMC manufacturer,
- inspect filters regularly and check for visible dust and grease build-up,
- pay attention to signs such as higher noise, reduced airflow or warning messages from the unit.
If filters appear heavily loaded or if the system indicates reduced performance, it is usually a sign that replacement should be planned. In more advanced systems, monitoring pressure drop across the filter can give a precise indication of when the filter has reached the end of its useful life.
Spending a few minutes to identify the right filtre VMC and combining it with regular, documented maintenance is an easy way to protect your home, your heat recovery system and the health of the people living there.