Finally, I understand
Why am I researching chimneys? We're planning to have a new house built and we're thinking through ideas for the design of it. I love the idea of a completely open fire, like this one:
Yes, that's Meduseld - the Golden Hall at Edoras, from the Lord of the Rings films. The hall just had a hole in the ceiling. It's design was based on the Viking halls and I'm wondering: did they fill with smoke, ever?
The site says:
Warm air in the house will exit through the open windows. The entire house then becomes like a big chimney. As air flows out through the windows upstairs, air is drawn from downstairs to replace it. This is called the stack effect, since the house acts like a stack, or chimney.
I think we're going to build a prototype miniature version and see how it works.