Question

How does a fan cool a human?

Answer 1

When the air circulates around us faster, the rate of evaporation increases.
So, the energy for evaporation is taken from you. "Evaporation causes cooling".

Answer 2

Does the rate of evalrization increase only because the 5 mm boundary layer is stripped away or because the vapor diffusion rate increases?

Answer 3

@koushik_ksv , out of curiousity, is the rate of evaporation increased due to the low pressure? Or the kinetic energy of the air acting on the perspiration?

Another thing is, the air around you is closer to your temperature, because your heat gives it the thermal energy! The fan pushes that air away, and puts other air in its place. The air around you might be cooler.

Answer 4

@theEric , you are right. If the body temperature is less than outer temperature, your theory works. Otherwise, it is primarily due to increased evaporation.

Answer 5

Thank you for your help!

Answer 6

Thank you!
\(\huge\color{#22CA55}{\large\ \ o\ o\ \\\smile}\)

Answer 7

NB: a fan does not cool an empty room