You can generate about 5 hours of cold air with one frozen gallon jug. 1. Drill 2-1/4" holes in the bucket to support the PVC pipe sections 2. Drill 2-1/8" holes in the liner that goes inside the ...

You can build it with a 5-gallon bucket, Styrofoam liner, PVC pipe, ice (or in this case, water frozen inside a milk jug), and a small fan. According to the video, it chilled air from 84 degrees F ...