Air extractor ventilator or VMC in the bathroom?

I was led to ask myself the question of the choice of the type of ventilation to remember in my bathroom when my installation, one fine morning, let me go

Given the humid weather, I looked into the subject quickly because I didn’t want to give time for mold to form here or there, especially since I really like this piece, which was particularly well cared for during the repair of the house.

Single-flow CMV (Controlled Mechanical Ventilation)

Already, let’s start from the obvious: for energy savings, houses are more and more hermetic, but nevertheless bad odors or steam must be evacuated and the air must be renewed; for this, houses often have a VMC (Controlled Mechanical Ventilation): these are the vents located on the walls or on the ceiling in the rooms of the house, whose ducts join the extractor which is often hidden in the attic.

Stale air is thus evacuated 24 hours a day. Those are the VMC simple flux which can also be, depending on the sophistication of the models, self-adjustable or humidity-controlled. There is also the VMC double flux which recovers the heat from the expelled air in order to reinject it into the home, which saves heating costs.


Ventilators are much simpler air treatment devices: they extract stale air from a room directly and occasionally to the outside via a specific duct. They are particularly suitable for water rooms such as the kitchen, bathroom or toilet. These aerators are intermittent and can be started in different ways, depending on the model and according to your needs:

  • ignition at the same time as a luminous switch,
  • manual ignition with a cord type switch,
  • timed ignition, the duration of which you decide,
  • ignition with humidity detector (hygrostat), for which you will decide the threshold hygrometry rate,
  • switching on when a presence is detected, thanks to an infrared cell.

To choose it, you will have to look at its flow rate in m3/h, its electrical consumption and its sound level. And check that they have a non-return valve which will prevent you from feeling a draft of fresh air entering in winter!

The air treatment equipment in my bathroom

As you will have understood, the VMC is installed during major rehabilitation work or during new construction, so it was totally unsuitable for my situation. On the other hand, the aerator, lighter and simpler in its installation for specific rooms, was well suited.

To replace my bathroom equipment, I chose a classic aerator coupled with a luminous switch: for barely 50 €, it extracts 95 m3/h, consumes only 8KW and has a very low noise level of 26.5 dB which is appreciable.

It also has an operating indicator light but in my case, I see little use for it. A very important point to clarify is the ease of installation: at the electrical level, 2 wires to be connected since there is no earth. Within everyone’s reach… and everyone!

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