12 August 2026 · 6 min read
The short answer
If you want every room conditioned from one system with nothing on the walls, choose ducted. If you want to cool one or two living spaces for the lowest upfront cost, choose a split system.
Most Sydney homes with three or more bedrooms and reasonable roof space end up ahead with a zoned ducted system, because zoning lets you run only the rooms you are using.
Upfront cost
A quality split system for a living room typically lands between $2,000 and $3,500 installed. A zoned ducted system for a four bedroom home usually starts around $9,000 and rises with the number of zones, roof access difficulty and switchboard upgrades.
Multi-head split systems sit in between: one outdoor unit driving two to five indoor heads, which suits apartments and homes with no roof cavity.
Running costs
Modern inverter systems in both formats are efficient. The difference is behaviour: ducted without zoning conditions the whole house every time it runs, so zoning is what keeps ducted bills sensible.
Splits are inherently zoned because each head runs independently, which is why they are hard to beat for a single-room application.
Roof space and building type
Ducted needs a roof cavity with enough height for the indoor fan coil and duct runs. Flat-roof homes, most apartments and some 1920s cottages simply cannot take it.
In those buildings a multi-head split or ceiling cassette is the practical answer, and strata approval for the outdoor unit location is worth confirming early.
Frequently asked questions
Is ducted air conditioning worth it in Sydney?
For homes with three or more rooms to condition and a usable roof cavity, yes. Zoned ducted delivers even comfort, adds resale value and keeps walls clear, and zoning means you only pay to cool the rooms in use.
Can I add more split systems later instead of going ducted?
You can, but three or four separate splits usually cost more in total than one zoned ducted system, and you end up with multiple outdoor units and wall heads.
How long does installation take?
A single split system is a one day job. A zoned ducted system in an existing home normally takes two to three days.