What is a multi-head split system?
A multi-head split system, also called a multi split, runs two or more indoor units from one outdoor unit. Each room has its own indoor unit and its own control, so you can heat or cool one room without running the others.
The other way to air condition several rooms is a separate split system in each room, each with its own outdoor unit. This service covers both. Ducted air conditioning isn’t covered.
Multi-head system or separate split systems?
Outdoor space. A multi-head system needs room for one outdoor unit. Separate splits need one per room, which can settle the question on a terrace, a narrow side path or an apartment balcony.
If the outdoor unit fails. With a multi-head system, every room it serves loses heating and cooling until it is fixed. With separate splits, only one room does.
Brand. The indoor units on a multi-head system have to be compatible with its outdoor unit, which in practice means the same brand. Separate splits can be different brands.
Running one room at a time. A split system sized for one room can run more efficiently than a larger outdoor unit serving just one indoor unit. Ask the installer how the suggested system performs when only one room is on.
Adding a room later. Separate splits can be added one at a time. A multi-head outdoor unit has a set capacity and number of connections, so ask whether it can take another indoor unit later.
Separate splits often suit better when the rooms are far apart, when you rarely use them together, or when there is space outside for more than one unit.
How much does a 2–3 head system cost?
The price for a dual head or three-head system depends on the number of indoor units, their total capacity in kW, the length of the pipe run to each room and how many walls the pipework has to go through. We don’t publish prices. A quote depends on the rooms and where the outdoor unit can go.
If the new system replaces a ducted gas heater, a Victorian Energy Upgrades discount may apply. The discount depends on the system installed and what it replaces. Only an accredited provider can apply the discount, so ask before you buy anything. The amount is confirmed in the quote.
Source: Heating and cooling discounts, Victorian Energy Upgrades (energy.vic.gov.au, page last updated 15 October 2026), checked 18 October 2026.
How do I size each room?
Each indoor unit is sized for its own room, from the floor area, ceiling height, windows and how well the room holds heat, and from whether heating or cooling matters more there. The installer then matches the outdoor unit to the rooms you will run at the same time.
Use the room lines in the form below: the room, its size in m² and when you use it. A request with those details can be quoted without a lot of back and forth.
Split system installation for one room Split system replacement