Question

Why do we feel cool under a fan when we perspire?

Answer 1

Evaporation — The process of liquid changing into vapours even below its boiling point is called evaporation.

• At a given temperature in any gas, liquid, or solid, there are particles with different amounts of kinetic energy.
  In the case of liquids, a small fraction of particles at the surface, having higher kinetic energy, is able to break away from the forces of attraction of other particles and gets converted into vapour.
• This phenomenon of change of a liquid into vapours at any temperature below its boiling point is called evaporation.
• A fan produces a feeling of comfort because our perspiration or sweating evaporates rapidly.
• Our body tries to cool itself by releasing sweat through the pores of our skin.
• When we sit under the fan, the sweat of our body evaporates due to directed air upon us making our body cool.