It is one of the ideal evaporation examples where water is pumped and the air is forcefully sent through it in a machine. The air gets cooled down as the water absorbs the heat from the air and makes the interior of a room cooler. The water, on the other hand, turns into vapour. This phenomenon of cooling the atmosphere by the use of evaporation is called evaporation cooling. It is also due to this effect the water cooler performs better on a hot and dry day.