Why spend hundreds of dollars on a portable A/C for your home when you can build one for $8! Pick up a styrofoam cooler ($4), one or two dryer vents ($2 each) and an old fan. Then, follow the simple instructions in the video below.

In just a few minutes, you’ll have your own homemade air conditioner that will last anywhere from 3 to 6 hours. It will drop the temperature of a single room quite a bit on a hot day!