"Evaporation" is the process of converting a liquid into vapor or gas. In order for this altered state to occur, heat energy must be used. For example, if you apply heat to water (the liquid), you can bring it to a boil and produce steam (the vapor).

In mist cooling, water mist is created by atomization and vaporizes naturally into the hot dry desert air. The heat energy used for this vaporization or "e-vaporation" process is obtained by absorbing heat from the air. As the heat is absorbed from the surrounding air, cooling occurs.

All mist cooling systems rely upon evaporation. The difference between various systems is how well they use and manage this natural phenomenon.