Types & how it works
How air conditioning works, the main system types, inverters, smart control, and how AC compares to heat pumps.
How does air conditioning work?
Air conditioning does not make cold air so much as move heat around. A unit takes warmth from the air inside your home and carries it outside using a refrigerant and a compressor, then blows the cooled air back into the room. That is the whole idea, and once it clicks the rest makes sense. Our guide to how air conditioning works takes it step by step without the jargon.
From there it is mostly about scale. A portable sits on the floor and vents through a window, and is the quick, no-install option for one room. A single split has a quiet indoor unit linked to a box outside, and cools one room properly. A multi-split runs several indoor units from one outdoor unit, and a ducted system hides the works and pushes cool air through vents across the whole house. As a rough sizing rule, plan for about 0.1 to 0.15 kW of cooling per square metre of floor, then adjust up for sunny rooms and high ceilings.
Two more ideas are worth knowing. An inverter unit varies its speed instead of switching fully on and off, which holds a steadier temperature and cuts running cost, and almost every good modern system uses one. The other is the link to heat pumps: a reverse-cycle air conditioner is an air-to-air heat pump, so the same box that cools in summer can heat in winter. Our guide to air conditioning versus heat pumps explains where the two overlap, and if you have seen the adverts, does Dyson make an air conditioner answers a common question honestly.
How it works
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Smart and Wi-Fi air conditioning explained
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Air conditioning vs fans: which actually cools you?
A fan moves air to make you feel cooler; air conditioning actually lowers the room temperature and dries the air. Here is what each really does, what they cost to run, and when a fan is enough versus when you need AC.
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Air conditioning vs heat pumps: can AC heat your home?
A reverse-cycle air conditioner is already a heat pump. Here is how home air conditioning and air-source heat pumps really compare, and which warms your home in winter.
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Dyson air conditioning explained: does Dyson make an aircon unit?
Dyson does not make an air conditioner. Here is what its fans, heaters and purifiers really do, why they cannot cool a room, and what to buy if you want real cooling.
9 Jun 2026
How does air conditioning work?
A plain-English guide to how home air conditioning works: it does not make cold, it moves heat. We explain the refrigeration cycle, the parts and the jargon.
4 Jun 2026How air conditioning works: common questions
How does air conditioning work? +
An air conditioner moves heat rather than creating cold. It passes warm indoor air over a cold coil filled with refrigerant, which absorbs the heat, then pumps that heat outside and releases it, blowing the cooled air back into the room. A compressor drives the cycle, which is why every refrigerant system has an outdoor unit.
What are the main types of home air conditioning? +
There are four common types. A portable is a movable floor unit that vents through a window. A single split pairs one indoor unit with one outdoor unit to cool a room. A multi-split runs several indoor units from one outdoor unit, and a ducted system pushes cooled air through hidden vents across the whole home. Portables need no installation, but splits and ducted systems must be fitted by an F-Gas certified engineer.
What is an inverter air conditioner? +
An inverter air conditioner varies the speed of its compressor instead of switching fully on and off. That lets it ease back once the room reaches the temperature you set, rather than blasting and stopping, so it holds a steadier temperature and uses less electricity. Almost every good modern split is an inverter model.
Is an air conditioner the same as a heat pump? +
In effect, yes. A reverse-cycle air conditioner is an air-to-air heat pump: it can run the cycle in both directions, cooling in summer and heating in winter. The main difference in everyday use is the label, since a cooling-only unit simply leaves out the heating mode. This is also why the same technology can qualify for heat pump grants.
More guides
To take it further, our buying guides help you pick a unit, installation covers getting a split fitted properly, and you can browse every guide in one place.
See the types in the catalogue
Compare wall-mounted, multi-split, ducted and portable units side by side, or find an installer to fit one.