With Bernoulli’s principle in mind (I think that’s the right one), is it more efficient to vent a room by putting a fan back from a window a bit, or right up next to it, and if so, is there a general sweet-spot as to how far back it should be?

Question

For context, this would be to vent a basement bathroom with a a window in an old house, and I can’t install a bathroom vent.

In: 857

Answer 1

I’m a firefighter and ventilation is part of our training.

The best way to vent a room is to place a fan back from the window, so that you can feel the fan moving air in an area just *slightly* larger than the opening of the window. This’ll be most effective.

[Here’s a neat video showing the effect.](https://www.youtube.com/watch?v=XP6oqIic4lo)