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The temperature is rising and if you live in Queensland, you’re probably already feeling the effects of another sweltering summer. If you’re considering the wonderfully cooling effects of air conditioning, you’ll know there are different types of systems, from window units and portable units to split systems and ducted air conditioners. (If you’re unsure of the difference between them, check out our handy guide on how to choose the best air conditioner).
Split systems are one of Australia’s most popular air conditioning systems and millions of homes across the country rely on them to beat the summer heat. Here is a guide to how split systems work, why you should choose one, the size you might need and the split system installation cost.
What is a split system air conditioner?
As the name implies, a split system air conditioner comprises two ‘split’ units — an outdoor unit (compressor) and an indoor unit (evaporator) that is placed in the room you want to cool. Because the unit requires pipes to connect the outdoor unit to the indoor unit (more on how it works below), there is no need to install a series of duct networks throughout your house, which is how ducted air conditioning works.
It is the ideal cooling solution for smaller properties and single-room climate control and is cheaper than a ducted system. Each indoor unit will typically only control the temperature of a single room, however, it is possible to have multiple units installed in your home that are connected to the single condensing unit outside.
How does a split system work?
Essentially, the indoor unit absorbs heat and transports it to the outside unit to be disposed of by a large fan coil unit that’s part of the condenser. The condenser blows air over pipes containing hot refrigerant gas, cooling and compressing it into a liquid before pumping it back to the evaporator inside your home.
Inside the evaporator, the liquid refrigerant is expanded, causing it to cool rapidly. The cool refrigerant absorbs heat from the air inside your home, and once it’s hot, it gets pumped back to the condenser outside, and the cycle begins again.The two units are typically connected by insulated tubes which are piped through a small hole in the wall.
Why choose a split system air conditioner?
A reliable, convenient and energy-efficient split system air conditioning unit can deliver impressive climate control and, if maintained regularly, will last between 10 and 30 years! There are lots of benefits to owning a split system, including:
- Affordability. They cost less than ducted systems to install and run if you have a smaller property with limited roof space. A set of tubes and electrical wires is enough to connect the outdoor and indoor units, which is a much more cost-effective option than ductwork. If necessary, you can also budget for additional units to be installed in different rooms later on.
- Efficiency. Split systems offer the capacity to control each air conditioning unit individually. This often results in cost savings because you can turn off a single unit when it’s not required. If you have multiple units, it also means you can control the temperature etc. of individual rooms, tailoring your cooling needs to what’s required.
- Star ratings. As of 2020, residential split-system air conditioners have to meet minimum energy performance standards (MEPS) according to the new zoned entry rating label for air conditioners sold in Australia. This means you can be assured that any new model you buy will be reasonably energy-efficient. When a manufacturer registers a model with the government’s Energy Rating system, the air conditioner gets a star rating label for cooling and heating based on its test results against the Australian standard for air conditioners. The more stars, the more efficient the model and the less it should cost to run, assuming it’s been correctly installed. A model with one or two stars is still OK, but a model with five or six stars is better, although more efficient models will probably be more expensive. Models will display this information on a label, whether you buy it in-store or online.
- Aesthetics and features. Split systems have sleek, modern choices that easily blend in with your current home decor in terms of size, colour and design. They are also typically available in floor, wall and ceiling-mounted models, so offer versatility.
- Quiet operation. Noise affects comfort and modern split systems are designed to minimise noise and run as quietly as possible. This is especially the case in bedrooms.
What size split system do I need?
Buying an air conditioner is a financial investment, so it should never be an impulse purchase as it affects your comfort levels and power bills. It might be tempting to buy the biggest air conditioner you can afford, but bigger isn’t always better. So, if you are asking the question, how do I calculate what size air conditioner I need, here is a guide.
The size of the room does dictate the capacity of the air conditioner you should buy, but it’s only one factor to consider. Four things have the biggest impact on the size of the unit you’ll need.
- Room size. What is the width, length and ceiling height of the room? The total volume of the room is also important as a room with high ceilings will require more energy to cool.
- Insulation. Are the walls and ceiling insulated, and what’s on top of and underneath the room?
- Location. Where do you live? A location with higher temperatures will need a more powerful air conditioner for cooling.
- Orientation. Which way does the room face? Large west- or north-facing windows can let in a lot of heat compared to southern-facing windows.
Some installers (and their online calculators) may recommend a larger capacity than you really need. Calculators should take into account all of the above factors and the more information you can include, the more accurate the calculation will be.
The cooling load calculators on the Fair Air website are offered by the Australian Institute of Refrigeration, Air Conditioning and Heating (AIRAH) and can help you decide.
Having a rough idea of the size of the system you’ll need is also helpful.
Room Size | Example | Approximate capacity |
SMALL (up to 20 sqm.) | Bedroom, study, small kitchen | 2 - 2.5 kW |
MEDIUM (20 - 40 sqm.) | Bedroom with ensuite, small lounge | 2.5 - 5 kW |
LARGE (40 - 60 sqm.) | Large bedroom, mid-sized lounge, large kitchen | 5 - 9 kW |
EXTRA LARGE (60+ sqm.) | Large lounges, open plan areas | 6 - 10 kW |
Why is choosing the right size important?
Choosing the right-sized system is vital. If it’s too big:
- The room can get too cold.
- Power use and running costs can increase.
- There is more wear and tear on the system.
- The unit may not dehumidify the air enough, so the room may feel less comfortable.
If it’s too small, it may have to run at maximum output more often, meaning:
- Power use increases.
- There is more wear and tear on the system.
- The unit dries out the air too much.
How much do split systems cost?
The total cost will depend on the price of the unit you select and the cost to install it. Split systems can vary dramatically in price, depending on:
- The brand and model.
- The size and capacity, ie. the kilowatts (kW) required (see the table above).
- Any Smart features such as ‘eco’ modes, sensors, Wi-Fi and app compatibility.
- The time of year (many retailers offer discounts on units at specific sales events and in the off-season).
Here is a rough guide:
Room size | Approximate capacity | Price guide |
SMALL (upto 20 sqm.) | 2 - 2.5 kW | $600 - $2800 |
MEDIUM (20 - 40 sqm.) | 2.5 - 5 kW | $700 - $3000 |
LARGE (40 - 60 sqm.) | 5 - 9 kW | $1000 - $5500 |
EXTRA LARGE (60+ sqm.) | 6 - 10 kW | $1500 - $5500+ |
How much does split system air conditioner installation cost?
Along with the cost of the unit itself, there will be installation costs. These can range from $600 to $800 plus depending on a range of factors. When quoting, a technician will consider:
- The number of units being installed.
- The size, type and brand of the unit.
- The complexity of the installation. For example, how much cabling or piping is needed, and where the unit will be located in your home.
- Any upgrades to your electrical system, if needed.
You will need a licensed air conditioner technician to install your system safely and legally to ensure your product warranty isn’t voided. They will need electrical qualifications to wire the unit into your home, and plumbing accreditation may be needed if the air conditioning drain has to be connected to your home’s waste water system.
Questions to ask your technician before the installation takes place include:
- What is your hourly rate?
- What is included in your service fees?
- How many people will be present at the property during the installation?
- How long will the installation take?
- Do you have a full air conditioning and refrigeration licence and an electrical licence, if needed?
- Do you have insurance and is the work covered by insurance?
How is a split system installed?
Split system air conditioner installation should only be carried out by a professional. The installation process may vary depending on the brand of the unit, but here is a guide.
- Your air conditioning technician will choose the ideal place in the room where the indoor unit will be placed. It will be away from direct sunlight and have open space around all sides.
- They will measure the height at which the unit will sit and fit the mounting place to the wall.
- They will create a hole about the mounting place for the piping to go through. Later in the process they will connect the pipes from the inside unit to the outdoor unit. A professional will know the type and length of pipe required to connect the units.
- Once the indoor unit installation is complete, they will install the outdoor unit.
- This involves finding a suitable place for it and ensuring it is not close to hot areas. Outdoor units can be placed on the ground or wall mounted.
- Once the indoor and outdoor units are secured, they will seal any holes in the walls.
References
- 2023, What Is Split System Air Conditioning? ComfyHome
- Pru Engal, 2023, How much does an air conditioner cost to install or replace? Choice
- 2023, Is a split system air conditioner right for your home? 6 benefits to consider. Mitsubishi Electric
- Alice Richard, What size air conditioner do you need? Choice