Why is the fan running or manual fan feeling cool?
When we feel very hot in the room in the summer, we often turn on the fan or hold the fan. Then we feel a little cool. Are the fans and fans that fan the air? Not. We can, through an experiment to prove it. Place the thermometer in front of the fan and then turn on the fan. What do you see?
The temperature that the mercury column on the thermometer indicates does not change. Take a wet cotton ball over the outside of the thermometer’s mercury bulb, then place it in front of the fan and turn on the fan. Now we see, the temperature that the mercury column on the thermometer indicates drops significantly. It turned out that the fan could not cool the mercury bulb; it only blew out the wind, could quickly make the wet cotton water evaporate quickly; the evaporation carries heat in the mercury bulb, so The mercury column immediately lowered.
Based on the small experiment above, we can understand the principle that explains why people feel a little cool when turning on the fan. On hot summer days, the outside temperature is usually higher than the body temperature; the body’s heat is difficult to spread out.