It is performed from old days to use the air to cool a thing.

Whizz to cool the hot water.
Blow with a fan.

It can be done with human power.

Whizz means that air is accumulated in the mouth and blows out at high pressure.
When industrialized, a compressor creates high pressure, accumulates it in a tank, and ejects it from a nozzle, but the principle is the same.

Hand fans have also been mechanized into electric fans, but the principle is the same.

In the 20th century, air conditioners appeared.
Introducing a cooling only type.

Compresses a heat medium such as alcohol or chlorofluorocarbon gas, condenses it into a liquid, evaporates it into a gas, and takes heat as heat of vaporization
The cycle of condensation → evaporation → heat release → compression is repeated.

The method of controlling the temperature with air is

1. Temperature control by increasing or decreasing the rotation speed of the fan
2. Control the temperature by controlling the air pressure by increasing or decreasing the rotation speed of the compressor
3. Control the temperature by controlling the opening of the air outlet (damper)
4. Control the temperature by controlling the opening of the amount of air blown by the pressure regulating valve
5. Temperature control by increasing / decreasing the rotation speed of the compressor and controlling the evaporation amount of the heat medium

And so on.