With the new thermal regulations, buildings are becoming increasingly isolated. If it's good for your heating bill, it's a lot less good for the indoor air quality that stays "trapped". To ensure the renewal of this air it therefore becomes mandatory to install a VMC.
A VMC to ventilate well
In a dwelling, it is essential to renew the ambient air. Often, a simple ventilation by opening the windows at least 15 minutes a day is not enough to bring enough fresh air. Humidity, unpleasant smells, pollutants and emissions from heaters are not all eliminated. The VMC makes it possible to satisfy all its needs, which has the consequence of ensuring the longevity of housing, improve the health and well-being of the occupantsand finally to ensure safety against combustion appliances, especially those operating on gas.
What is a VMC?
The VMC (or mechanical controlled ventilation) is a system that consists of several elements (in the case of a VMC single flow):
- a motor that is in the form of a box, with a fan that allows to extract stale air and circulate the air
- a set of ducts in which the air circulates
- one or more extraction mouths that determine the volume of air extracted
- air inlets to bring in fresh air
How does a VMC work?
To avoid possible noise, the extractor is often installed in the attic. He sucks air through extraction vents in all rooms most exposed to pollution or humidity such as bathroom and kitchen. By sucking the air, it creates a vacuum that mechanically get outside air through ventilation grilles or air inlets above the windows of other rooms, and thus ensure a natural renewal.
The different types of VMC
There are 2 main families of VMCs: VMC single streams and double streams. In the category VMC simple flux, we distinguish the models Self-adjusting (which ensure constant flow throughout the year) models hygroadjustable whose airflow fluctuates with the indoor air humidity rate.
If there are only the extraction vents that are humidity-controlled, this is a VMC hygro A. If the air inlets are too, we talk about VMC hygro B. The latter is the most effective model to fight against humidity but also to limit any heat loss when the air circulates.
Unlike the single flow VMC, dual flow ventilation works by closed circuit and does not require the installation of air intakes. The extractor placed under the roof is replaced by an exchanger that recovers calories from the air absorbed in the service rooms to heat the air then blown, and properly filtered, in the other rooms. In BBC homes, this system also serves as a heating system in winter and as a "cooling system" in summer. It is also a very expensive and more complicated model to install than a single stream VMC.