Split System vs Ducted Air Conditioning: Which Wins in Canberra?

Split systems start around $1,850 installed for a 2.5 kW bedroom unit. A whole-of-home ducted install runs $11,500–$19,500 for most 3–4 bedroom Canberra homes.

But that's not the fair comparison. To match the whole-of-home comfort of a ducted system you'd need 3–5 splits — around $8,000–$13,000 installed — with a wall unit visible in every room.

Adjusted like-for-like, ducted is often only $3,000–$5,000 more than the equivalent multiple-split solution, and it delivers noticeably better comfort. That gap has narrowed further in 2025–26 as ducted inverter technology has become the default from Daikin, Mitsubishi Electric and ActronAir.

Splits are more efficient per kW, but ducted systems benefit from zoning — you only heat/cool the rooms you're using. In practice, a well-zoned ducted system runs 15–25% cheaper than the equivalent multiple-splits it would take to condition the whole home.

The efficiency win depends on how you use it. Households that leave the ducted system running to the whole house 24/7 will spend more than an equivalent split setup. Households that zone bedrooms overnight and living areas during the day will spend materially less.

In our Canberra data, well-zoned ducted homes average around $600–$900 a year in heating and cooling electricity. Poorly-zoned or always-on ducted homes push $1,500–$2,000.

Ducted wins on comfort every time. Every room within 1–2°C of setpoint, no wall-hung boxes, ceiling vents disappearing into the ceiling.

Splits struggle with room-to-room comfort. Even a well-placed split leaves the far corners of an open-plan area 2–3°C off setpoint, and doors have to stay open for it to reach adjoining rooms.

Split systems win when comfort is only needed in one or two rooms — home offices, a master bedroom, a single studio flat. In those cases ducted is overkill.

This one is subjective, but real. A ducted system is invisible — only slim ceiling registers show. Split systems put a 900 mm plastic box on the wall of every conditioned room.

For heritage homes, high-end renovations and new builds, ducted is almost always the choice for this reason alone.

In Canberra, ducted reverse cycle is one of the top-3 features buyers ask about. It typically adds more to resale than it costs to install, particularly in the $900k+ suburbs where buyers expect it as standard.

Splits add resale value too, but on a diminishing scale — one split is a plus, three splits is neutral, five splits starts to look like a workaround for the absence of ducted.

Splits are quick — most single-head installs are done in a day, no ceiling access needed beyond a small penetration for the pipework.

Ducted takes 2–4 days for a standard 3-bedroom home and requires roof access. In Canberra's older housing stock (Kambah, Weston, Curtin) roof space can be tight — we sometimes need to specify low-profile fan coils or add a small bulkhead. Your installer should tell you this at quote stage, not on install day.

New build or major renovation, three or more bedrooms, in for the long term: ducted. Roof space allows, budget stretches to it — you won't regret it.

Existing single-storey home, no major renovation planned, targeting 2–3 rooms of comfort: two or three splits. Cheaper, faster, and gets 80% of the benefit for 50% of the cost.

Apartment or townhouse without roof space: multi-split. One outdoor unit feeding 3–5 indoor heads. Body corporate approval usually straightforward in Canberra.

Studio or single bedroom with occasional use: one properly-sized split. Anything more is over-engineering.

A common Canberra solution is ducted for the main living zones and bedrooms, plus one split in a converted garage, granny flat or upstairs studio that the ducted system doesn't reach. Best-of-both, and often what you'll see at the higher end of Canberra's renovation market.

Good zoning: bedroom zone, living zone, master suite zone, upstairs zone, plus at least one dedicated study or media room zone. Six or more independently controllable zones on a standard 3-bedroom home.

Bad zoning: two zones (day/night) on a whole house. The system either overheats the small rooms or under-heats the big ones — you get the worst of ducted's cost and the worst of splits' unevenness.

Constant-volume vs variable-volume zoning matters too. VAV (variable air volume) systems modulate airflow per zone; CAV (constant air volume) dumps excess air to a bypass — less efficient but cheaper.

Single-storey brick veneer with a pitched roof: straightforward. Roof space is usually adequate, cornice access allows registers, and the outdoor unit sits on a side path.

Double-storey with a cathedral ceiling: harder. Bulkheads may be needed, or the second storey goes on splits while the ground floor is ducted. Common hybrid.

Slab-on-ground with a low pitch (many Mawson, Chifley, and Curtin homes from the 60s): often needs a bulkhead down a hallway to hide the main return-air trunk.

Heritage overlay (some inner-north): outdoor unit placement needs approval. Expect an extra week or two of lead time and possibly a discreet screening solution.

Zone-per-room splits for a 3-bedroom home: master + main living + one child bedroom (as a swing zone). Total ~$8,000 installed. Covers 80% of the comfort of ducted for 55% of the cost.

One large living-room split (6–7 kW) plus small bedroom splits (2.5 kW each). The living-room split does the heavy lifting on hot afternoons and cold evenings; bedroom units are only used for sleep.

For units that share a wall with an outdoor courtyard: multi-split reduces the outdoor unit clutter substantially and keeps single-outdoor aesthetics.

Per-year service cost is close: ducted with one indoor fan coil is $280–$400; three splits are $180–$240 each ($540–$720 total). Splits win on the marginal cost per unit; ducted wins on convenience — one service booking rather than three.

Deep cleans work the same way: one ducted fan coil is $260–$400; three splits are $660–$900 total. But splits accumulate mould individually — a rarely-used spare-room split can be filthy while your main living-room unit is fine.

A ducted system with a well-placed fan coil is close to inaudible in living areas. You hear a faint whoosh from vents, nothing more.

Splits mount directly above where you live. Even a whisper-quiet unit at 22 dBA is audible in a bedroom at night, and cheaper units at 32–36 dBA can wake light sleepers.

If noise sensitivity matters (nurseries, home offices, master bedrooms), that alone can push the decision to ducted.

Adding a fifth head to a 4-head multi-split by 'daisy-chaining' pipework — voids warranty and unbalances the system.

Using undersized pipework because the run is short — the system operates outside spec forever.

Skipping return-air sizing on a ducted retrofit — restricts airflow, kills efficiency, shortens fan life.

Same 3-bedroom home, same setpoints, same occupancy pattern:

Three splits (living, master, kids' room shared): approximately 3,200 kWh/year on heating and cooling combined.

Zoned ducted (6 zones, sensible schedule): approximately 3,600 kWh/year but conditioning every room to comfortable temperatures, not just three.

Adjusted for square metres conditioned, ducted is materially more efficient per m² conditioned. That's the answer to the 'ducted is expensive to run' myth — it's only true if you run it dumb.

Home A — 1985 brick veneer, 140 m², Kambah. Owners chose three splits (living 7.1 kW, master 3.5 kW, kids' room 2.5 kW) for $8,400 total. Two years in they added a fourth split in the second bedroom for $2,400 because it was noticeably colder than the rest of the house. Total spend $10,800, four visible wall units, comfort described as 'good, not great'.

Home B — 2005 double-brick, 190 m², Bruce. Owners went ducted from the start, 14 kW zoned across six zones, $15,200. Six years in, no additions, one filter clean per year plus an annual service. Comfort described as 'we never think about it'.

Home C — 2018 6-star build, 210 m², Denman Prospect. Owners went ducted with eight zones and premium controllers, $19,800. Solar and battery paired. Annual heating and cooling bill under $500. They pre-heat on solar between 10 am and 2 pm and coast through the peak tariff window every evening.

The pattern across dozens of similar comparisons: ducted's higher up-front price recovers over 5–8 years in comfort, resale, and running-cost efficiency, once you factor in the reality that split-only setups usually grow into 4–5 units anyway.

'Can we start with ducted and add splits later?' Yes — a common approach in staged renovations. Design the ducted for the main areas first and leave provision for splits in future additions like garages and studios.

'Can we start with splits and add ducted later?' Rarely worth it. You end up paying twice — once for splits that become redundant and once for the ducted retrofit.

'Will splits handle a two-storey home?' Usually yes for bedrooms upstairs, but you'll want one bigger unit downstairs. Multi-split is often cleaner than three separate outdoor units.

'What if we only heat, never cool?' Reverse cycle still wins — cooling is a bonus you'll use on Canberra's 20+ 30°C+ days each summer.