How does Air Conditioning work?


Air Heaters are easy to understand, it’s basically just running electricity through a wire, so that excess energy turns into heat. Heating is easy enough that you can do it in the form of a campfire with primitive tools.

Air Cooling is a lot harder. I can’t think of a single way to just up and cool air without the use of something that’s already cold.

So how does Air Conditioning work?

(If it’s just some specific obscure chemical reaction then I’ll be disappointed)

In: Technology

A compressor takes electrical or mechanical power and uses that to compress a refrigerant gas. That gas is then released into a series of coils where it can expand in volume. That expansion causes the gas to become very cold, which makes the coils very cold. Air is blown over the cold coils, which cools the air. The cool air is then blown through ducts to cool the building/car/whatever.

Air conditioners *do* use chemicals to cool the air, but it’s a change of state and not a chemical reaction that make this occur. Freon is a rather popular chemical used in ACs, and this is first introduced into the system as a gas. The chemical of choice is condensed into a liquid form, creating pressure and the desire to be gaseous again. This chemical is then reintroduced into a low pressure chamber, where it wants to expand. This expansion requires energy, which comes from the heated air that is brought into the system from outside, or possibly inside based on the setup. The expansion of this chemical sucks the energy from the air to expand and revert to a gas form, and the rest of the system takes the cool air and circulates it through.

This isn’t a perfect explanation, and more information can be found [here](

Edit –
It’s also worth noting that the chemicals that are chosen for this, stay cold in this system, but would rather not outside of it. Its like freezing water with pressure, the gasses are kept cold because of the environment they are in. After heating the freon, or other chemicals, the gasses pass through radiators to transfer that energy outside of the system, to be cycled through again.

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First thing you should understand is that heat is just a measure of how much something is vibrating in the molecular scale. Hotter something is, the more the particles vibrate. Colder, the less vibration.

The a.c. first compresses a special gas on the outside half of the a.c. unit. Gasses vibrate constantly and when they are compressed together, they’re now squished together and vibrate against each other. Kind of like you rubbing your hands together. This generates a lot of heat as you can imagine. This heat is pumped to the outside air. Either by being outside in the first place or by a pipe.

As it generates heat, the particles are slowing each other down. Think of it like friction.

Once the gas has slowed down enough under pressure, it turns into a liquid. This liquid is pumped to the indoor side of the a.c. and is then relieved of the pressure. This liquid normally wants to be a gas and so it quickly evaporates. However remember that the particles gave up a lot of its speed rubbing against each other, so in order to gain enough energy to go back into a gas, it grabs energy from its surroundings. This being the air inside your house, cooling your house down.

When this gas has equalized in temperature to your house again, it is pumped back to the outside half of the a.c. unit and the cycle restarts.

Its not 100% accurate but its the easiest way to understand.