My in-window fan has an option to direct the air outward instead of inward. I have absolutely no idea what the purpose of this is, but I am loving the white noise it creates without making my room cold, since the temperature dropped a bit over the last couple of days (and that it drowns out my neighbor’s child, whose goal in life seems to be to see how loudly and for how long he can pointlessly scream).
If it drowns out a noisy moppet, it’s already justified.
But directing the air outward — the “exhaust” setting — has a purpose besides white noise: it sends indoor air outside, which is useful if that air isn’t all that wonderful. (There’s a reason why all bathroom fans are exhaust fans.) I’ve been known to use a fan for white-noise generation myself; if the room doesn’t need cooling, I turn it away from me. Slightly different pitch, but similar results.