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The Basics Of How An Air Conditioner Keeps You Cool

Understanding the basics of how an air conditioner works can be more beneficial than you’d think, and it may surprise you to learn that there is no single part of an air conditioner that makes the air cool. Instead, it works by taking advantage of a basic scientific process; namely, as liquid converts to a gas, it absorbs heat. An air conditioner forces specialised liquids to do this over and over again, absorbing heat and expelling cool air in the process. It’s actually a simple concept that uses some very clever machinery to make it work.

The Parts Of An Air Conditioner

air conditioning parts

Obviously, individual air conditioning systems might have variations in their design according to their manufacturer and setting (for example, one in a hotel is going to be slightly different to one only cooling a house), but they all share the same basic principles, and each of them use the following:

Refrigerant – a carefully-chosen liquid that has the chemical ability to change to a gas at very low temperatures.

  • Evaporator coil – the part that turns the refrigerant from a liquid to a gas.
  • Compressor – the part that puts that gas under high pressure, generating heat.
  • Condenser coil – turns refrigerant from a gas to a liquid, expelling this heat and cooling it again for the next cycle.
  • Fans – keep air moving through the whole system.
  • Ducting – the channels through which the cool air is distributed throughout the building.

So now you’re familiar with the parts involved, here’s how they all fit together!

The Simple Version Of How An Air Conditioner Works


Before we get into too much depth in terms of the mechanics, we’ll introduce you to the underlying structure of the whole system. Essentially:

1. The air conditioner draws in warm air from your office, usually through a grille.

2. One of the internal fans blows that warm air over the cold, low-pressure evaporator coil that contains the refrigerant. (A dehumidifier removes excess moisture at this stage, too.)

3. The refrigerant is cooler than the air, so the heat from the warm air transfers into the refrigerant instead, leaving the air cool and dry.

4. The cool air is then sent back out through the ducting to the rest of the building.

5. Meanwhile, the refrigerant, now hot and gaseous from the heat transfer, is processed using the compressor and condenser coils. During this procedure, the unwanted heat is released outside and the newly-cooled refrigerant is moved through an expansion valve. Once this happens, it’s rendered ready to cycle back to the evaporator, and continue chilling more incoming air.

That’s the basics covered! If you’re ready to hear more detail, read on.

How The Cool Cycle Continues

The crucial thing to understand about the cooling process is that as the refrigerant absorbs the heat from incoming warm air, the heat causes it to change to a gaseous state. Obviously, if that process only happened once the air conditioner would have a very short lifespan indeed, so the system needs to continue cycling the refrigerant back and forth from a gas to a liquid to indefinitely cool incoming air.

So, once the refrigerant has been changed to a gas by Step 3 of the process above:

1. It is moved to the other side of the air conditioner unit and put through the compressor, which subjects the gaseous refrigerant to very high pressure. This creates heat energy.

2. This hot, now high-pressure refrigerant gas passes from the compressor into the condenser coil. In short, the condenser separates the heat energy from the refrigerant, and turns the latter back into a liquid.

3. The heat energy is blasted outside through an external unit, while the newly-cooled refrigerant is channelled the other way; back towards the evaporator, ready to start the cooling cycle all over again.

And that’s more or less all there is to it! Well, sort of. Obviously, the average air conditioning unit is a highly advanced piece of equipment, and though we’ve covered the basics of its workings here we’d still never advise trying to fix any problems yourself. Instead, we recommend you take advantage of the peerless knowledge and expertise of our own HVAC technicians here at Askews.

A regular service and maintenance contract can prevent many problems before they have a chance to properly develop. Call us on 01282 863 7825, or click here to get a free quote!

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