Why can electric fans and hand fans make people feel cool?

In the summer, when we feel very hot in the room, always wanting to turn on the fan or hand fan, it may feel a little cool. Is the electric fan and hand fan cooling the air? Not that we can prove this point through experimentation.

Put the thermometer before the electric fan blowing you see what? The mercury column on the thermometer indicates constant temperature: on the outside of the mercury mercury thermometer embraces a wet cotton bridge, and puts the pre-electric fan back, while we see the temperature indicating the water column. The bank on the thermometer has dropped clearly. It turns out, electric fans can't blow the mercury bridge that the fan blows out, which can cause water in the wet cotton bridge to quickly evaporate; The heat in the mercury bridge evaporates, the mercury column drops.

Based on the small experiment above, we can understand why when people stand in front of the fan feel cool.In the hot summer, the surrounding temperature is always higher than the body temperature, the body heat is not easily dispersed. People can then regulate their body temperature by sweating, because the evaporation of sweat can release heat from the body. Blowing fans are to promote air circulation around the human body, but air circulation is the effective way to increase the ability to evaporate sweat. The faster the sweat evaporated, the easier it was for the body heat to emit and they felt cool.

In the hot summer, the surrounding temperature is always higher than the human body temperature.(Illustration).

During hot days without wind, sometimes the temperature is not too high but people feel uncomfortable. Sometimes the temperature is high but the weather is not windy, people feel cool. The main reason is the human sweat evaporation and the fast rate of different radiant heat.