Evaporation plays an important part in the earth's water cycle. Water evaporated from the earth by the heat of the sun later falls as precipitation. Because evaporating molecules absorb heat from their surroundings, evaporation functions as a cooling process. Air-conditioning and refrigeration systems contain evaporators that remove heat and moisture from the surrounding air and so reduce the temperature. The evaporation of perspiration cools the skin.
Evaporation provides a way to separate mixtures.
The resulting liquid contains a greater proportion of the more volatile substance than does the original mixture. Such products as alcoholic beverages and gasoline are manufactured by distillation. Evaporation also serves as a means of concentrating nonvolatile substances. For example, the juice from sugar cane is heated until nearly all the liquid evaporates. This process produces a concentrated sugar solution from which sugar crystals form.