An air conditioner controls more than temperature indoors. It also controls the amount of moisture, movement, and purity of the air. We have come to depend on air conditioning systems to keep us comfortable during the summer months.
The machine used in air conditioning works very much like the one in a kitchen refrigerator. Both depend on a fast-evaporating liquid like Freon to rapidly chill whatever it comes in contact with.
When you turn on the switch of an air conditioner, fresh air passes through a filter to remove dust, and an electric motor starts circulating liquid Freon from a compressor through pipes or coils. As the Freon is being pumped through the coils, it absorbs the heat from the coils, and cools them and the air around them.
The added heat then causes the Freon to evaporate into a gas. At this point, an electric fan blows the cold, clean air out through the air conditioner vents into the room. The Freon becomes a liquid again as it returns to the compressor. This cycle keeps going until the system is shut off.
Since the 1940s, all new buildings and factories and many private homes have been designed to include air conditioning. Ships, airplanes, offices, restaurants, theaters, shops, and space vehicles make use of this steady flow of comfortable, purified air.