Air conditioning.
Most people think that air conditioners lower the temperature in there homes simply by pumping cool air in.
Whats really happening is the warm air from your house is being removed and cycled back in as cooler air.
This cycle continues until your thermostat reaches the desired temperature.
An air conditioner is basically a refrigerator without the insulated box. It uses the evaporation of a refrigerant to provide cooling.
This is how the evaporation cycle in an air conditioner works…
A compressor compresses cool refrigerant, causing it to become hot high pressure refrigerant, this hot refrigerant runs through a set of coils so it can dissipate its heat and it condenses into a liquid.
The liquid runs through an expansion device and in the process it evaporates to become cold, low pressure refrigerant.
This cold refrigerant runs through a set of coils that allow the refrigerant to absorb the heat in the air drawn in by the fan and return cool air inside the building.