Systems: multi-split
Multi-split air conditioners: how multi-head split systems work and what they cost
Short answer
A multi head split system costs about $4,500 to $12,000 installed in 2026 on a standard single-storey install. A two-head system is usually $4,500 to $7,500, a three-head system $6,000 to $9,500 and a four-head system $8,000 to $12,000.
Prices are estimates, not quotes (how we estimate them). Rebate rules checked September 2026.
Compare 3 quotes for my houseA multi-split is one outdoor compressor feeding two or more indoor units in different rooms. Each room gets its own head and its own remote. Outside, you have one box on the wall or slab instead of three or four.
It sits between a single split and ducted. You condition several rooms without cutting a roof full of ducts, which is why it suits double brick, apartments, and homes where the roof space is tight or not yours to touch.
It is also the system with the most caveats. One compressor running several rooms is efficient when it's sized right and a single point of failure when it isn't. This page covers how it works, what it costs, and when separate splits are the better buy.
What is a multi-split air conditioner?
A multi-split air conditioner connects several indoor units to one outdoor unit. Each indoor unit has its own refrigerant pipe pair running back to the outdoor unit, and each can be switched on, off or set to its own temperature.
Makers sell outdoor units by the number of ports. Mitsubishi Electric's Australian range runs from two-port to six-port outdoor units, and Daikin says its Super Multi NX outdoor units connect up to five indoor units. The outdoor unit's total capacity has to cover the heads you connect to it.
The indoor units don't all have to be wall heads. Mitsubishi Electric says its multi-split outdoor units work with wall mounted, floor standing, ceiling concealed, ceiling cassette and ceiling suspended indoor units. So a lounge can have a floor console or cassette while the bedrooms have ordinary wall splits.
What is the difference between a split system and a multi-split?
A standard split system is one indoor head paired with its own outdoor unit. A multi-split is several indoor heads sharing one outdoor unit. That is the whole difference, and it drives every pro and con below.
| Separate splits | Multi-split | |
|---|---|---|
| Outdoor units | One per room | One for all rooms |
| Heating one room, cooling another | Yes | No. All heads run in the same mode |
| If the compressor fails | One room goes down | Every room goes down |
| Wall space outside | Lots | One unit, but longer pipe runs |
| Installed price, 3 rooms | Often similar or lower | Often similar or higher |
| Installer licence | Restricted split licence allowed | Full refrigeration and air conditioning licence required |
How much does a multi head split system cost?
Budget about $4,500 to $12,000 installed for most homes in 2026. The number of heads is the biggest driver, then the pipe runs. A two storey home where the pipes have to find a way down through a wall cavity costs more than a single storey with all rooms on one side.
| System | Typical use | Installed price |
|---|---|---|
| 2 heads | Lounge plus main bedroom | $4,500 to $7,500 |
| 3 heads | Lounge plus two bedrooms | $6,000 to $9,500 |
| 4 heads | Lounge plus three bedrooms | $8,000 to $12,000 |
| 5 or 6 heads | Whole small home | Quoted individually, and often close to small ducted money |
Get a quote for separate splits in the same rooms at the same time. Two or three single splits sometimes come in cheaper than one multi, because single splits are sold in far bigger volumes. If they do, you get independent systems for less money. When you get up to three local quotes, ask for both options on the same page.
Is multi-split air conditioning good? The pros
- One outdoor unit instead of several. That matters on a small courtyard, an apartment balcony or a narrow side passage.
- No ductwork. It suits double brick, flat-roofed homes, heritage ceilings and apartments where the roof belongs to the owners corporation.
- Each room has its own head and remote, so bedrooms can sit at different temperatures within the same mode.
- Rooms can use different indoor styles: wall heads, a floor console in the lounge, a cassette in the kitchen.
- The inverter compressor slows down when only one head is running, so a well-sized multi isn't burning power for empty rooms.
What are the disadvantages of a multi-split air conditioner?
- One compressor, one point of failure. When the outdoor unit stops, every room loses heating and cooling at once.
- All heads run in the same mode. You can't heat a cold south bedroom while cooling a hot west lounge. Mitsubishi Electric notes each room picks its own temperature within the same mode.
- Longer pipe runs from one outdoor unit to far rooms, which can mean more visible pipe covers on the outside of a two storey home.
- Adding a room later is only possible if the outdoor unit has a spare port and spare capacity. Plan the final room count now.
- Fewer installers are licensed to do it. ARCtick's restricted split licence doesn't allow multi-head installs, so you need a tradie with the full licence.
Common problems with multi-split systems
Most multi-split complaints trace back to design, not the product. The outdoor unit is sized to the sum of the heads without thinking about which rooms really run together, or a small bedroom head is paired with a big outdoor unit and short-cycles.
The others are ordinary split problems multiplied: blocked condensate drains on one head, a pipe joint that leaks on a long run, or a head mounted where it blows straight onto a bed. Ask the installer to explain how they sized the outdoor unit and where each pipe will run, in writing. Every installer we match holds a current ARCtick licence, and you can get up to three local quotes with that sizing spelled out.
Multi-split vs ducted: which is better?
Ducted is better for a whole house with good roof space: it's quieter, the vents are discreet, and zoning handles five or more rooms well. A multi-split is better for two to four rooms in a home where ducts are hard or impossible. Above four or five heads, a multi-split starts to cost what a small ducted system costs, and ducted usually wins on comfort.
Compare ducted air conditioning prices against a multi for your house before you decide, and read the split vs ducted guide for the running cost side.
Choosing and sizing a multi-split
Size each room first, then the outdoor unit. Our size calculator gives a starting kilowatt figure per room. The outdoor unit then has to support the combination of heads, and the installer should check that against the maker's combination tables, not guess.
Stick with brands that have deep service networks, because you're putting several rooms on one compressor. Daikin, Mitsubishi Electric and Fujitsu all sell multi-split ranges here. Check the warranty covers the outdoor unit and every head the same way.
In Victoria, reverse cycle multi-splits can qualify for a Victorian Energy Upgrades discount when they replace gas heating. The discount comes off the invoice through an accredited provider. See the Victorian rebate page, or get up to three local quotes and have each installer show it on the invoice.
Sources
FAQ
Common questions
What is multi-split air conditioning?
It's one outdoor unit running two or more indoor units in different rooms. Each room has its own head and remote. Most home systems run two to five heads, and some outdoor units take six.
Is multi-split air conditioning good?
Yes, for two to four rooms in a home where ducts are hard to install. It saves outdoor space and avoids ductwork. The trade-offs are a single point of failure and all heads running in the same mode.
What are the disadvantages of a multi-split air conditioner?
If the outdoor unit fails, every room loses heating and cooling. All heads must run in the same mode, so one room can't heat while another cools. Pipe runs are longer, and adding a room later needs a spare port.
What is the difference between a split unit and a multi-split unit?
A split has one indoor unit and one outdoor unit. A multi-split connects several indoor units to one outdoor unit. Separate splits are independent. A multi shares one compressor.
How much does a multi head split system cost?
Typically about $4,500 to $12,000 installed in 2026 on a standard install. A two-head system is usually $4,500 to $7,500, a three-head $6,000 to $9,500 and a four-head system $8,000 to $12,000. See the multi-split cost guide.
What are common problems with multi-split AC?
Poor sizing of the outdoor unit against the heads, blocked drains, leaks on long pipe runs, and heads placed where they blow onto people. Most come down to the design and install, so ask how the installer sized it.
Which 3 way multi-split air conditioner is best?
There's no single best. Daikin, Mitsubishi Electric and Fujitsu all sell three-head systems with strong service networks here. Pick on sizing, warranty and the installer's local service record, then compare itemised quotes.
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