A box fan in the window will work, but don't expect miracles.

Yes, a box fan can work as a temporary exhaust fan to push cooking smells outside, but it’s a hack, not a solution.

The trick is orientation. Put the fan in the window facing out, with the grille flush against the screen or open frame. You want it sealed as tight as possible — use cardboard, tape, or a foam block to fill the gaps around the sides. Otherwise, half the air just circulates right back in. And make sure the fan is stable. Propping it up with random stuff is a recipe for a crash.

Won’t be as good as a real exhaust fan. Box fans aren’t designed for static pressure, meaning they struggle to push air through a narrow gap. You’ll get some airflow, but don’t expect it to clear heavy grease smoke fast. Also, the blades are exposed — keep the fan away from curtains and definitely don’t let it suck up oil vapor right into the motor. Grease buildup on a plastic fan blade is a fire hazard you don’t want.

If you’re in an apartment with no range hood and you’re desperate, it’ll do. But spring for a proper window exhaust fan if you cook a lot. Future lungs will thank you.