If hot air rises and cool air falls, how does an open window downstairs end up cooling the upstairs in winter?

Question

If hot air rises and cool air falls, how does an open window downstairs end up cooling the upstairs in winter?

In: 7

Answer 1

Even though the hot air will tend to be displaced upwards, the downstairs air is going to be in direct contact with the outside world through the window. This will cause the cool air to chill further (Bearing in mind that the outside air is likely colder than the “cold” air inside. And the warm air is resting on top of that cooling air, which will tend to swap warmth from that volume of warmer air.

Essentially, there is a thermal conduit from the warm upstairs air and the cold air outside.