Necessity makes men genius, that’s why Heat Recovery Ventilation (HRV), which systems are produced by Airplast, was invented in the 70s, to meet the needs of the Scandinavian population to insulate their houses from the cold and at the same time clean the indoor air from humidity and pollution. Simply opening a window, at such low temperatures, was advised against for the obvious reasons. From there, the need to find a way to clean the air without excessively cool down the house was a fact. In addition there were factors such as the nordic attention towards hygiene and silence, and the...