Systems: split
Split system installation: cost, sizes and what to buy in 2026
Short answer
A split system air conditioner costs about $1,500 to $4,800 installed in 2026 on a standard single-storey install. A 2.5 kW bedroom unit is usually $1,500 to $2,500, and a 5 to 7 kW living room unit $2,100 to $3,900.
Prices are estimates, not quotes (how we estimate them). Rebate rules checked September 2026.
Compare 3 quotes for my houseA split system is the air conditioner most Australian homes start with. A slim indoor head goes high on the wall, an outdoor unit sits on a bracket or a pad outside, and two copper pipes, a drain and a cable join them through a hole about the size of a fist.
Buy reverse cycle and it heats as well as cools. Buy inverter and it slows down instead of switching on and off. Almost every split sold here now is both, which is why a good one is the cheapest way to properly condition a room.
If the lounge is the room you live in, one well-sized split is often the whole answer. This page covers how splits work, what size you need, what they cost, and what separates a good install from a bad one.
What is a split system air conditioner?
It's called a split because the system is split in two. The noisy part, the compressor, lives outside. The quiet part, the fan and coil, lives inside. Refrigerant carries heat between them. In summer it pulls heat out of the room and dumps it outside. In winter a reverse cycle split runs backwards and pulls heat in from outside air, even on a cold morning.
Most splits are wall mounted high-wall units, which is what people mean by a wall mounted air conditioner. The same outdoor-and-indoor idea also comes as floor consoles, ceiling cassettes and bulkhead units, and as multi-split systems where one outdoor unit runs several rooms. For a plain-English walkthrough, read what is a split system.
What is an inverter split system, and does it save power?
An inverter compressor changes speed to match the load. It runs hard to get the room to temperature, then throttles right back and ticks over. An older fixed-speed unit could only run flat out or stop, so it cycled on and off and the room swung around the set point.
The saving is real in normal use, because most of a split's running hours are spent holding a temperature, not chasing one. It's also quieter and holds a steadier temperature. The one catch is repair cost: inverter boards cost more to replace than the simple parts in an old unit, which is another reason to buy a brand with a proper service network.
Almost every reverse cycle split sold in Australia now is an inverter. If a quote is for a non-inverter unit, ask why.
What size split system do I need?
About 100 to 140 watts of cooling per square metre suits a typical insulated room, as our sizing guide explains. West-facing glass, high or raked ceilings, poor insulation and open stairwells push it up. A shaded brick room pulls it down.
| Size | Typical room | Approx. area | Installed price |
|---|---|---|---|
| 2.5 kW | Bedroom, study | Up to about 20 m² | $1,500 to $2,500 |
| 3.5 kW | Large bedroom, small lounge | About 20 to 30 m² | $1,700 to $2,700 |
| 5 kW | Lounge, open kitchen-dining | About 30 to 45 m² | $2,100 to $3,300 |
| 7 to 8 kW | Large open-plan living | About 45 to 65 m² | $2,600 to $4,300 |
| 9 kW and up | Very large open-plan living | About 65 m² and up | $3,400 to $4,800 |
Don't oversize to be safe. A unit that is too big cools fast, shuts down and leaves the room clammy. A unit that is too small runs flat out all afternoon and still loses. The right size is the cheapest one to live with. Unsure? Get up to three local quotes and each installer sizes the room properly.
How much does a split system cost to install?
The installed price is an estimate for a standard single-storey job: the unit, labour, a short back-to-back pipe run and a basic electrical connection. What pushes a split past the standard price is the install, not the badge: a second storey (about $275 to $800 more), pipe beyond the standard run ($45 to $155 a metre), a double brick wall, a hard-to-reach outdoor location, a new circuit ($300 to $900), a switchboard upgrade ($1,000 to $3,500), or an old unit that needs removing (about $95 to $150).
Retailer install packages usually cover a standard back-to-back install only, where the indoor and outdoor units sit either side of the same wall with a short pipe run. Anything else is priced as an extra on the day. Read what the package excludes before you compare it with a local installer's quote. A licensed local installer quotes the actual wall, so get up to three local quotes for a like-for-like number.
Full breakdown and worked examples are in the split system installation cost guide.
What does a split system cost to run?
A modern reverse cycle split in a decent lounge, run hard on a hot afternoon, often costs $0.40 to $0.90 an hour depending on its size and your tariff. Holding temperature on a mild day costs a fraction of that, because the inverter backs off.
The biggest running cost lever is the thermostat. Around 24°C in summer and 18 to 20°C in winter keeps bills sensible, and each degree beyond that adds several percent. Read the best aircon temperature or put your own numbers into the running cost calculator.
Household single-phase splits must carry the Zoned Energy Rating Label. It shows heating and cooling stars and annual energy use for hot, average and cold climate zones, plus noise levels for the indoor and outdoor units. Compare the stars for your zone, not the headline.
Which split system brand should I buy?
Brand matters less than sizing and installation, until something breaks. Then service coverage matters a lot. Daikin, Mitsubishi Electric and Fujitsu cost a bit more and are easy to get serviced for the life of the unit. Mitsubishi Heavy Industries and Panasonic are often the value picks in the premium tier.
The warehouse special is fine if you like living with a dead outdoor unit in year six. Our ranked picks by room and budget are on the best split system air conditioner page, and the quietest bedroom units are on quiet air conditioners for bedrooms.
Split system installation: where the units go
- The indoor head goes high on a wall strong enough to hold the mounting plate, with the clearances the maker's installation manual asks for above and to the sides. Plasterboard needs to be fixed into studs.
- Back-to-back is cheapest: the outdoor unit sits directly behind the indoor head on the other side of the wall.
- The outdoor unit needs free airflow in and out. Jammed behind a fence or in a narrow side passage, it works harder and gets noisy.
- Keep the outdoor unit away from a neighbour's bedroom window. NSW, for example, restricts the hours an air conditioner can be heard inside a neighbour's home.
- The condensate drain needs a fall to a safe outlet, not dribbling down the wall or onto a path.
- Apartments usually need owners corporation approval for the outdoor unit and any wall penetration. Heritage homes may need council sign-off for a unit visible from the street.
The installer handling refrigerant must hold an ARCtick licence. A restricted split licence covers single-head splits under 18 kW, and the electrical work needs an appropriately licensed electrician. Every installer we match holds a current ARCtick licence. Get up to three local quotes.
Split system, multi-split or ducted?
One or two rooms: separate splits. Two to four rooms with no roof space: a multi-split or separate splits, priced side by side. The whole house, with good roof space, or replacing gas ducted heating: ducted. The full decision is in split vs ducted.
In Victoria, an efficient reverse cycle split can earn a Victorian Energy Upgrades discount, applied at the point of sale by an accredited provider. In NSW, the Energy Savings Scheme can take a smaller amount off. Check your postcode on the quote page.
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Common questions
What is an inverter air conditioner?
It's an air conditioner whose compressor changes speed to match the load instead of switching on and off. It reaches temperature, then slows down and holds it. Almost every reverse cycle split sold in Australia now is an inverter.
Does an inverter aircon really save electricity?
Yes, in normal use. Most running hours are spent holding a temperature, and an inverter does that at low speed instead of cycling on and off at full power. The saving shrinks if the unit is badly oversized or undersized.
Is it better to leave an inverter AC on all day?
Not usually. An empty house still costs money to cool. Use the timer to start it 20 to 30 minutes before you get home. On a very hot day with people home, leaving it running at 24°C is fine, because an inverter holding temperature draws far less than one fighting a hot room from scratch.
What is the disadvantage of an inverter AC?
Higher repair costs. The inverter board and variable-speed compressor cost more to replace than the simple parts in an old fixed-speed unit. Buy a brand with a good local service network and keep the warranty paperwork.
Which is better, a reverse cycle or a split system?
They aren't alternatives. Split system describes the layout, an indoor and an outdoor unit. Reverse cycle describes what it does, heating and cooling. Most splits sold here are reverse cycle, and that's the one to buy.
Is reverse cycle aircon expensive to run?
No, not compared with most alternatives. A modern reverse cycle split often costs $0.40 to $0.90 an hour running hard in a lounge, and much less holding temperature. It is usually cheaper to heat with than a plug-in electric heater.
How much does a split system cost installed?
About $1,500 to $4,800 in 2026 for most homes, on a standard single-storey install. A 2.5 kW bedroom unit is usually $1,500 to $2,500 and a 5 to 7 kW living room unit $2,100 to $3,900. A second storey, a long pipe run, a new circuit or switchboard work adds to that. See the split system cost guide.
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