I am always on the look out for doing something cheap. I like the fog chiller design with the 10' section of 4" PVC full of ice, but gagged at how expensive 4" PVC has gotten. I have been keeping an eye out for cardboard carpet tubes at a local carpet place I drive by, and I have been seeing more plastic tubes lately. Then it struck me, these may be ideal to make a fog chiller out of. So I grabbed some, and will be seeing how cheap I can make a functioning fog chiller for. The tubes are approximately 4 1/2" in diameter.