Explained – How an Air Conditioner Works

How does an air conditioner work? I have heard many people wonder about this out loud but have never been able to answer their question. So, I decided to find out the answer – and I can share it with you!

An air conditioning unit can be a bit baffling. It seems to takes hot air out of your house and then blows in new cool air. But the air conditioner unit outside the house is very hot and blows hot air. Just where does this cool air originate?

In fact, an air conditioner does not have some secret store of cool air to blow into your house. It just seems like it is removing the air and blowing in new cooler air! In reality, an air conditioner is only removing the heat from this air and then releasing the heat outside.

It achieves this feat using four basic components:

1. The compressor

2. The condenser

3. The expansion valve

4. The thermostat

The process starts with the refrigerant, like freon, entering the compressor. This is usually located on the outside of the building. The compressor compresses or squeezes the refrigerant into a very hot gas under high pressure.

While remaining under pressure, the gas passes through a series of tubes or coils called the condenser. The heat dissipates into the surrounding air during this process so that the gas has turned into a cooler liquid once it reaches the end of the condenser. It is still under high pressure at this point, however.

The liquid is then passed through the expansion valve into another series of tubes at a lower pressure that are inside the building being cooled. The evaporation point for the refrigerant is much lower than it is for the water so the low pressure allows it to evaporate or turn into a gas again. The act of evaporating draws the heat out of the air. A fan blows over the coils to assist the process. Finally, the refrigerant is passed into the compressor to begin the process again.

The air conditioner keeps running until the thermostat detects that the inside air temperature is at the desired level at which point the air conditioner is switched off. Once the air temperature raises above a certain threshold, the unit switches on again and extracts more heat.

There you have it – the secret of an air conditioner revealed. It is based on basic physics principle that evaporating liquids absorb heat. All the machinery around an air conditioner is simply to mange this basic principle. Next, time you are a party and somebody wonders about this topic, you can be a super geek and give them an answer!