I don't think a tiny crack makes that much difference. I also live in a -20 area. Also the colder it is, the easier venting happens, so a small crack has the same effect as having the window open much more in summer.
I can't remember the total, but I recall seeing a calculation about this and it didn't amount to very much energy, especially if the bedroom heat isn't on super high.
Anecdotal, but I've heard the Germans often tend to keep a window open a bit year round, and I know my grandma did even in winter. She was pretty frugal too.
I can't remember the total, but I recall seeing a calculation about this and it didn't amount to very much energy, especially if the bedroom heat isn't on super high.
Anecdotal, but I've heard the Germans often tend to keep a window open a bit year round, and I know my grandma did even in winter. She was pretty frugal too.