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AC from A to Z: the air conditioning terminology you need to know

woman reading air conditioning terminology guide

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Condenser coils? 


Split systems and VRF?

When you apply these phrases to air conditioning, the meaning starts to get a little hazy. Like any technological or mechanical terminology, it’s not part of your everyday vernacular, so when it comes to getting air conditioning installed or even getting your existing unit serviced, keeping up with your air conditioning technician can be a bit of a struggle.

While an experienced air conditioning technician will explain things in a way you’ll understand, it’s also good to know some of the basic air conditioning terminology so you can get to know your AC better and understand what your technician is doing to help improve its performance. 

In this blog, we share some common terminology you’ll find in your air conditioner’s manual, or things you air conditioning technician might discuss with you. Read on!

Central air conditioning 

AC from A to Z: the air conditioning terminology you need to know -

In the movies, you’ll often hear people talking about “central air” – otherwise known as central air conditioning. In this process, air is cooled in a central location like an indoor or outdoor unit and distributed around the house or business via fans and ductwork.

This is an American term – here in Australia, you’re more likely to hear it called “ducted air conditioning”.

Image result for no greater sin than central air"


Image: giphy


There are two kinds of coils inside your air conditioning unit – a condenser coil and an evaporator coil. These coils work together to achieve the perfect temperature for your home or business, and one is useless without the other!

Evaporator coil:

The evaporator coil is where cool air comes from. Normally a “U” or “A” shaped tube inside the indoor unit, the evaporator coil is where the air conditioning refrigerant absorbs heat which is then carried outside to the condenser coil.

Before entering the evaporator coil, the refrigerant passes through an expansion valve. This valve relieves pressure from the liquid refrigerant and cools it. The liquid refrigerant leaving the expansion valve is quite cold, allowing it to absorb heat from the air.

Condenser coil: 

You can find the condenser coil inside your outdoor air conditioning unit.

After the refrigerant absorbs heat from inside the house, the refrigerant then travels outside to the condenser unit via a copper tube. The refrigerant gas enters the compressor, pressurises, and turns into hot, high-pressure gas.

Then we move onto the condenser coil where the refrigerant releases the heat absorbed from the house. Your outdoor unit has a fan that blows cool air over the condenser coil and cools off the refrigerant. 

Then, voila – cool air in your home!

Ducted air conditioning

AC from A to Z: the air conditioning terminology you need to know -


Image: Apex Air Conditioning

Ducted air conditioning is one of the most effective ways to heat and/or cool your home all-year-round. The internal unit is installed in the roof-space of your home or business and through a series of interconnected ducts and individual controls, you can easily control the temperature of each room. 

This is also called “zoning”.

Ducted air conditioning is known to be more energy efficient than other forms of air conditioning – up to three times the heating/cooling output for every kilowatt of electricity used! The unit is also quiet and discreetly tucked away, so you’ll hardly even notice you have air conditioning at all.

Ducted AC is ideal for large homes and businesses.

Multi split-system

AC from A to Z: the air conditioning terminology you need to know -

Multi-split system air conditioning units are ideal for large homes and businesses that need temperature control in each individual room. This system consists of an outdoor unit which connects to multiple indoor units throughout your home or business, and the indoor units can be controlled via remote.

Thanks to the outdoor unit, multi-split system installation is easy and flexible to install, while also saving space indoors.

Split system

AC from A to Z: the air conditioning terminology you need to know -

Split system air conditioning is the most common choice for homeowners. Cost-effective (around $2K on average), simple to install, and perfect for cooling or heating single rooms or open areas, split system air conditioning is a great option for homeowners who don’t want to spend a fortune on air conditioning.

The indoor unit is sleek and modern in design, while also not taking up too much room on the wall. It’s remote-controlled for convenience and can be installed in one day.

VRF systems

AC from A to Z: the air conditioning terminology you need to know -

VRF systems (otherwise known as “variable refrigerant flow systems”) are one of the most complicated and high-end forms of air conditioning. A VRF system has one outdoor unit and multiple indoor units, making them perfect for office buildings, apartment buildings, and other large businesses.

It’s a smart piece of technology – it recognises the user’s desired temperature via the indoor control panel but also takes note of the outside temperature, then uses logic to achieve the best temperature indoors. 

Because VRF systems operate at varying speeds, they’re optimal for saving energy – home and business owners can save up to 55% on energy with a VRF system!


Zoning refers to the heating and cooling of different rooms or areas in a house. There are usually separate controls for each room, so the optimum temperature can be achieved based on each room and each person’s preference.

Sometimes there are opening and closing dampers in each zone, so the air conditioning can also be manually controlled.

Now you know the ABCs of air conditioning!

While the inner workings of your air conditioning is complicated, chatting about it with your air conditioning technician doesn’t have to be. 

With the basics now under your belt, you can follow along with your technician more easily, and understand what work needs to be done to either install or service your unit.

At Air Conditioning Industries, we’re committed to explaining our work and our practices in a way that’s easy to understand. With more than 60 years of experience, we know a thing or two about AC – and our team is more than happy to run through the process with you from start to finish, so there are no questions left unanswered.

Have a question for one of our team members?

Get in touch with our Newcastle-based team today. We can provide more information on air conditioning terminology and provide free quotes for service & installation.