Is Evaporation a Cooling or Heating Process?

Evaporation is a cooling process. It occurs because some particles in a liquid acquire more than average kinetic energy. Thus, when these particles escape from the liquid's surface as vapor or gas, they leave a cooling effect due to energy loss.

Examples of evaporation are the drying of clothes on a clothing line and the drying of sweat on a person's body. Evaporation normally happens at room temperature, which is usually lower than the particular liquid's boiling point. When temperature increases, the evaporation rate increases. Wind, which replaces the locally humid air with dry air, also quickens the evaporation rate.