Which method is more effective (and why) for recirculating air into a room: a) using a fan to blow air out of a window, or b) using a fan to blow air in through the window?

Question

For context, I’ve got a basement room in an old house that isn’t tied in to central air conditioning, and sometimes the air gets a bit stale.

It has a basement window, so I’ll open that up and stick a fan in the window to blow air out, but someone told me that it’s better to have the fan outside and pulling fresh air in.

The room won’t be overpressured as it’s got a big gap under the door, and the fan doesn’t cover the whole window.

In: Physics

Answer 1

Always blowing out, fans “take” air from all direction not only from the back so unless there’s a duct to make sure the air is coming from outside you’ll be just moving mostly the same air. Blowing out creates a current that makes the air go out so it gets replaced