Multi-Split Air Conditioning: Cool Multiple Rooms Without Going Ducted

What is a multi-split air conditioning system?

A multi-split air conditioning system connects one outdoor unit to multiple indoor units. It allows you to cool several rooms independently without installing ductwork, making it ideal for homes with limited space or specific zone requirements.

Multi Or Split System?

You want to cool more than one room, but ducted seems like overkill. And installing multiple split systems? That’s more outdoor units taking up space, more cost, and more demand on your switchboard.

Enter the multi-split system.
This smart setup allows you to control the temperature in multiple rooms using a single outdoor unit without sacrificing efficiency or design.

Here’s how it works, who it’s for, and what to know before your air conditioner installation.

1. What Is a Multi-Split System?

Unlike a traditional split system (which has one indoor unit per outdoor unit), a multi-split system connects two to five indoor units to a single outdoor unit.

Each indoor unit is controlled independently so you can:

• Cool the bedroom at night
• Keep the living room cool during the day
• Turn off rooms you’re not using

It’s zone control without ducts and that makes it perfect for many Brisbane homes.

2. Who Should Consider a Multi-Split?

Good fit if:

• You want to cool 2 to 4 rooms
• You don’t have space for multiple outdoor units
• Ducting isn’t possible due to layout or renovation restrictions
• You want control over individual rooms, not full-house cooling
• You want energy savings by only cooling the spaces you need

Not ideal if:

• You need to cool more than 5 rooms
• Your switchboard or mains power is undersized
• You prefer full centralised control from a single thermostat

We can assess your layout and tell you if it’s a fit during a quote visit.

3. Pros and Cons of Multi-Split Systems

Pros:

• Fewer outdoor units = cleaner façade
• Individual room control
• Lower power consumption than ducted for small setups
• Great for townhouses, upstairs-only installs, or units

Cons:

• Initial cost can be higher than separate split systems
• Requires careful pipe layout and pressure balancing
• All indoor units rely on the same outdoor unit (if it fails, all zones go offline)

Our Aircon Installers are experienced in balancing these systems correctly.

4. How We Design Your System

When Precision designs a multi-split system, we:

• Size each indoor unit based on room volume, insulation and usage
• Calculate total outdoor load (kW and circuit capacity)
• Match brands with known reliability (e.g. Mitsubishi Heavy, Daikin)
• Plan pipe routing to avoid unnecessary ceiling or wall access
• Check if your switchboard can support the system or quote an upgrade

This prevents airflow imbalance and improves long-term performance.

5. Can You Add More Units Later?

Some models support expansion. For example, you might install two rooms now, and a third unit in future provided the outdoor unit was sized to allow it.
We’ll flag that in the design if expansion is part of your long-term plan.

6. Is It More Efficient Than Separate Splits?

Not always but it can be, especially if:

• Rooms are used at different times
• You’re replacing window units or ducted in an older home
• You want a neater external layout with just one condenser

Multi-split systems shine when layout and aesthetics matter.

We go into more energy tips in our Energy-Efficient Cooling Guide.

FAQs

How many rooms can a multi-split system cool?

Usually 2 to 5 rooms, depending on the model and total cooling capacity.

Can I control each room separately?

Yes. Each indoor unit has its own remote and temperature settings.

Is a multi-split cheaper than ducted?

In small homes—yes. Multi-splits are often cheaper to install and run if you’re cooling select rooms, not the entire house.

Can it be connected to solar?

Yes. Inverter multi-splits pair well with rooftop solar if usage is timed with sunlight hours. See our solar guide.

Final Thoughts

Multi-split systems are one of the smartest ways to cool multiple rooms without committing to ducted air or cluttering your home with outdoor units.

We’ve installed hundreds across Brisbane homes—and we’ll help you decide if this flexible, efficient setup is the right fit for your space, your power supply, and your budget.