All you need is two buckets, a pump and a fan. The fan pumps air into larger bucket, on the other hand the pump from the small bucket sends the cold water into the larger one. This exchange of elements causes the heat exchange, causing a cooling effect. Another advantage that this DIY air conditioner gives to your living space is that it also filters the air. So, in case you have been smoking cigarettes or pot slyly, hiding under your bed, then this might help by taking out the smell. Of course, you will have to spend some time and money in making it. As for the details, if you are really interested in making one, then you can see that here. And, I know hiding under the bed was little too much.
Via: Gizmodo