jeffwTIL about “passive houses,” building that are airtight and require barely any energy to heat or cool
TDCNTo people who says “they aren’t airtight” are not correct. Living in a country where building houses like this is the norm I can say that they are build to be as airtight as possible to keep in humidity and thereby heat inside. What makes them livable and not a humid moldy plastic bag is a well tuned mechanical ventilation system with a heat regeneration system (air cross flow system, really simple actually) that recovers most of the heat. The ventilation system runs 24/7 and keep the air fresh, more fresh than most conventional houses in fact if it’s tuned correctly that is. But yes the house is as airtight as posible and they pressure test them to ensure they meet the standards.
The biggest issue with it is actually cooling them. We have issues here in summer because no method of removing heat is properly implemented yet. But in winter it’s awesome. My heating bill is practically 0.
dlpklSo from the article it seems that when the passive air vents are closed the total flow of air is supposed to be less than 10m³/hm². The air flow that occurs during the test is from cracks and leaks in the fixtures and doors. Calling it airtight might be confusing since people assume that would mean zero net flow.
I can see that might being confusing if you are not used to it, but houses are build to be “as airtight as practically posible” of course you could never bild a normal hous as airtight as a spaceship, but if you look at windows doors etc of a passive house you’d see rubber gaskets and seals everywhere. New tech keeps coming up. All houses since early 2000 here are required to have an inner airtight membrane and there are strict requirements about how to apply it. All seams, corners and nail holes etc. must be taped with special membrane tape. In theory the only holes in the house should be the ventilation system. I’m my current apartment even the kitchen hood is connected to the ventilation system so when it runs and an even amount of air is being exhausted and injected back into the house to avoid any pressure differential, minimizing leaks from the inevitable tiny leaks here and there. Airtight is the goal and we are damn close. Many houses are also better than the standards to account for small leaks over time.