Talking back about the isolation tips given before in that blog, you may realize that we have been looking for a complete isolation between the outside air and the inside air.
Further illustrating that concept, you may take a look at the pressure testing (so called blower test) required by the passiv haus institut certification.
Now, once isolated, your house behaves like a thermal container and the humidity generated inside is now contained too (humidity generated by the wet rooms like bathrooms, kitchen, etc. or generated by the human breathing). Without any control, such a humidity concentration may become a source of bad feelings, a source of moistures on the wall, and worse, a source of diseases (allergies, etc).
The right humidity concentration should be within the 40%-60% range.
Fortunatelly, solutions are available:
- Centralized Mechanical Ventilations (Simple or double flux)
- Canadian well
- Humidity regulator controlling the ventilation speeds.
Actually you need to implement the above three solutions together in order to maximize the ventilation efficiency whilst reducing the waste of inside heating or cooling effort. The canadian well brings a significant contribution to that.
By the way I strongly believe that the Ventilation Simple Flux combined with the Canadian Well is good enough to fullfil the target. In other words, the Ventilation Double Flux generates useless extra-cost in such a configuration.