I created that thingy to cool my room. Before we had central air, my room would get pretty hot in the summer. I decided to go ahead and create what I would call the Cheap & Small Air conditioner.
This project cost me nothing, just some stuff that I had lying around in the house. The fans came from an old air hockey table.
Build time: Aprox 1 hour
EDIT: I had to redo a lot of the writing in there, I'm better now with English.