Ducted vs Split System Air Conditioning in Perth: Which Is Right for Your Home?

What is the difference between ducted and split system air conditioning?

A split system has one outdoor condenser and one indoor wall-mounted head that conditions a single room or open-plan area. A ducted system has one outdoor unit and a single large indoor fan-coil unit in the roof space, which pushes conditioned air through insulated ducts to ceiling vents in every zoned room. Both are refrigerated reverse-cycle systems, so both heat in winter and cool in summer.

Multi-head splits sit between the two: one outdoor unit feeds two to five indoor heads. They suit homes where ducting is impossible, but each head is still a wall unit and the outdoor unit is a single point of failure.

Ducted vs split system: side-by-side comparison

How much does ducted air conditioning cost in Perth?

For a typical three or four bedroom Perth home, a ducted reverse-cycle system with four to six zones lands between $8,000 and $15,000 installed. The spread comes from capacity (12 kW to 18 kW is common), the number of zones, the brand tier, and how hard the roof space is to work in. Older homes with low-pitch tile roofs or limited ceiling access sit at the top of that range because of labour.

Budget for an electrical upgrade if your switchboard has no spare capacity. A ducted system needs its own dedicated circuit, and homes with older boards sometimes need a board upgrade before the installer can connect it.

How much does a split system cost installed in Perth?

A 2.5 kW split system for a bedroom typically costs $1,500 to $2,500 installed. A 7 kW to 8 kW unit for an open-plan living area typically costs $2,500 to $4,000. Back-to-back installs, where the indoor head sits on the same wall as the outdoor unit, are cheapest. Long pipe runs, two-storey installs and units mounted on brackets add cost.

Which costs more to run?

Per room, a split system wins. A modern 2.5 kW inverter split draws roughly 0.5 to 0.8 kW while cooling, which is around 20 to 25 cents per hour at Perth's current residential tariff of about 32 cents per kilowatt-hour. A 14 kW ducted system draws roughly 4 to 5 kW when all zones are open, around $1.30 to $1.60 per hour.

The comparison changes with how you use it. A ducted system with only two zones open is throttled back by its inverter and can cost similar to two splits. A ducted system with every zone open cooling empty rooms is the most expensive option in the house. Zoning discipline is the single biggest lever on a Perth ducted power bill. See our running cost guide for the full worked examples.

Does ducted air conditioning add value to a Perth home?

Yes, in the sense that buyers in Perth now expect it in family homes and price its absence in. Agents commonly list ducted reverse-cycle as a headline feature. Split systems are treated as neutral: not a negative, but rarely a selling point. If you plan to sell within five years and the home is three bedrooms or more, ducted usually returns most of its cost in saleability. If you plan to stay, choose on comfort and running cost instead.

Which suits Perth's climate?

Both. Perth's summer is hot and mostly dry, with a typical January maximum around 31 degrees and a run of days above 35 each year. Refrigerated reverse-cycle of either type handles that comfortably. The climate question matters more when you compare refrigerated to evaporative cooling, which struggles on humid afternoons and sea-breeze days; we cover that separately.

What Perth does affect is sizing. West-facing living areas, black roofs, and poorly insulated 1970s and 80s homes need more capacity per square metre than a modern build with a light roof and good insulation. As a rule of thumb, allow 100 to 120 watts per square metre for a well-insulated room and 130 to 150 for a hot, west-facing or high-ceiling room, then confirm with an on-site assessment.

When a split system is the better choice

• You cool one to three rooms most of the time, typically a living area and a main bedroom.
• You rent, or you plan to sell within a couple of years.
• The home has no usable roof space, such as a flat roof, an apartment or a raked ceiling.
• You want to stage the spend: one unit now, another next summer.
• You want redundancy. If one split fails in February, the others keep running.

When ducted is the better choice

• Three or more bedrooms and a family that uses most of the house.
• A new build or major renovation, when ducting is cheap to run and easy to hide.
• You value a clean look with no wall units or external pipework.
• You want one controller, one filter, one service and app-based zoning.
• Resale within five to ten years in a suburb where buyers expect ducted.

The hybrid option most Perth homes overlook

Many larger Perth homes end up with a ducted system for the living zones plus a dedicated split in the main bedroom. The split runs overnight at low cost while the ducted system stays off, and the ducted system covers the busy daytime spaces. It is not the cheapest install, but it is often the cheapest to run over a summer, and it gives you a backup if either system fails.