Are U sick and tired of too high temperature when U are trying to sleep ?
Step 1: Getting Started
U need: 1 large polystyreen case, 1 polystyreen sheet, 3 tubes of some kind, an old desk fan ventilator and 4-8 frozen bottles of water(1,5 liter). It works excellent, and does not have that annoying feature that hot air needs to be ventilated out of the room. 4 frozen bottles of water gives you 10-12 degrees cold air for 5-6 hours.
Step 2: Watch Those Fingers!
Cut the polystyreen sheet so it fits in a approx 65 degree angle. U should leave 10 cm of space in the bottom, and a tight fit in the top.
Step 3: Ventilation Holes
Cut out 3 holes for the tubus. The 3 tubes are mounted in the side of the box. They should point upwards, as cold air flows downwards.
Step 4: Fan Hole
Mark the diameter of your fan in the lit. Cut the hole.
Step 5: The End
Place the fan over the hole, and enjoy the cold stream of air.
I know this doesn't win any design awards, but it gets the job done.