A system similar to this can also be used for cooling rooms and buildings. A lot of the world's population lives on the tropical belt, in hot conditions. A lot

A system similar to this can also be used for cooling rooms and buildings. A lot of the world's population lives on the tropical belt, in hot conditions. A lot of them use air conditioning, and a lot more are going to start using it in coming decades. A simple system, that cools a room down about 5 to 10 degrees Celsius, would be a great way to reduce dependence on fossil fuels.