Passive House Principles: Balanced Ventilation
So back to the vapour issue. The cure to the problem is an HRV, (or an ERV), the differences of which I will discuss in a later post. The HRV provides a supply of fresh air to the interior of the structure, while at the same time, expelling the stale polluted air to the outside. However the simple exchange of air would be like having a window open. When its hot outside, all that hot air comes inside and has to be cooled. When it's heating season, all that cold air outside would draft through the open window and make it extremely cold and hard to heat.
|Very little water passes through drywall via diffusion.|
|A hole in drywall moves bulk air carrying moisture.|