Holmes Window Fan | $15 | Amazon
If you’re trying to cut down on your electrical bill, a window intake fan like this one can pull the cool night air into your bedroom with only a trickle of electricity. If you live in, like, Texas, it’s probably not going to do you any good until November or so, but if you live above the Mason-Dixon line, you can probably already put it to good use. At $15, it’s never been cheaper.
They also boast that you can manually flip the fan around in the window to turn it into an exhaust fan, which is a frankly hilarious selling point.