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

Blow out. Open a window or two on the other end of the house from the fan. Also get a ceiling fan going inside to prevent a single unmixed river of air flowing straight through. I usually blow out all night then blow in to the main room while I’m getting ready for work. Then close up the house to keep the cool in.