I wanted to experiment with them and see if they would work. I went with the bucket design, and it works.
My RV mods: DIY swamp cooler
I realize this would not work in a location where humidity is too high, but it is a fun project to do. I am trying to think of a design better suited for RV use, where the air intake would come from outside.
Are any of you using evaporative coolers (swamp coolers) ?