Exactly How Does An Aircon Work?

Air conditioning works by using a cycle of heat absorption and ejection to cool the air inside your home, with key components like the evaporator, compressor, and condenser playing crucial roles in this process.

If you want to understand how your aircon keeps you cool, keep reading.

The Basic Principle Behind Air Conditioning

Air conditioners make hot air inside your home go away and send it outside. They do this by using a special chemical, often called coolant or refrigerant, which takes the warm air from your rooms.

This is all about moving heat from one place to another. The key player in this magic act is the evaporator coil – it’s where the cool happens. Inside this coil, the coolant changes from liquid to gas as it sucks up heat from indoor air passing over it.

This amazing process happens over and over again in a cycle – take in hot air, use coolant to grab that heat, then push the warmed-up coolant outside where another part of your air conditioner dumps that heat out into the open air.

It’s like a superhero team: every piece has its job that helps create a cooler space for you and keeps you comfortable even when it’s really hot outside.

The Air Conditioning Cycle Explained

The air conditioning cycle starts when warm air inside your room hits the cold evaporator coil. This coil has a cooling agent that takes in heat from the air. The refrigerant captures warmth, turns from liquid to gas, and moves to the compressor.

Here, it gets squeezed and becomes hotter.

Next, this superheated vapour travels to the condenser outside your house. The outside air helps cool down the refrigerant, which gives away its heat and changes back into a liquid state.

Then this chilled coolant cycles back indoors through expansion valves that make it colder again before reaching the evaporator coil. This loop keeps going until your home reaches the temperature you want on your thermostat – ensuring you stay cool!

Stage 1: Heat Absorption Inside Your Home


A close-up photo of an air conditioning unit's evaporator coil.

Your air conditioning unit starts its magic by pulling hot air from inside your home. It uses a special chemical coolant that flows through coils, much like how water takes in the sun’s warmth.

This liquid travels around the evaporator coil, which works like a sponge soaking up heat.

As warm air passes over the chilled coils of the evaporator, the coolant inside absorbs all that thermal energy. The once-hot air begins to cool down and gets ready to make your room nice and chilly! Meanwhile, our helpful coolant has trapped all that unwanted heat and is about to take it on a journey outside.

Stage 2: Heat Ejection Outside Your Home

The air conditioning unit works like a magic box that takes the warmth from inside your home and tosses it outside. Think of it as a heat mover. The special chemical coolant that grabbed the hot air from your room now gets pumped to the back of the AC, where something called a condenser lives.

This part has coils too, just like in stage one.

Here’s what happens: The warmed-up coolant arrives at these coils super-hot because it turned into a gas when it sucked up all that indoor heat. Now, outside your house, fresh air blows over these coils through a big fan in the unit.

As this happens, the outdoor air grabs hold of all that heat from the coolant. Like water off a duck’s back, the heat is shed into the outdoor air and away from your comfort zone! This turns our gaseous friend back into liquid form so it can circle again and keep you cool!


Air conditioners are clever machines that take heat from inside and put it outside. They use a special liquid that picks up the warm air and carries it away. This cool trick happens over and over to keep our homes nice and fresh.

Knowing how this works can help us fix problems with our AC units. Remember, cooler homes are just one smart machine away!


1. What does an aircon do to make the air cool?

An air conditioner uses a special heat transfer process to take warmth out of the room and blow in cold air.

2. What are the main parts of an air conditioning system?

The key parts of most systems include an evaporator that makes heat turn into liquid, ducts that spread the cold air and a unit outside that releases hot air.

3. How is an aircon like a refrigerator?

Just like your fridge keeps food cool, an AC unit takes warm indoor air and cools it down by moving heat outside, much like how a refrigerator works but for your entire room or building.

4. Does turning on my AC clean the indoor air?

Yes, when you switch on your AC not only does it cool down your space but often it has filters that can trap dust and smoke particles leading to cleaner, better quality indoor air.

5. Can having good AC help stop me from getting too hot or sick in summer?

Absolutely! An efficient HVAC system with cooling can prevent illnesses caused by high temperatures such as heat stroke because it helps control how warm spaces get.

6. My friend says their conditioner is ‘split’ – what does this mean?

A split-air-con means there are two main parts: one part inside blowing cool thermal exchange)air into the house and another part outside taking away superheated vapor through evaporation.