Costs, Price Factors and 2026 Rebates
Ducted vs split system air conditioning: upfront cost, running cost and which suits your home
How ducted reverse cycle and split system air conditioning compare in Australia on installed price, running costs, zoning, noise, looks and future replacement.
For most Australian homes, split systems cost less to buy and usually less to run per room, while ducted reverse cycle costs more upfront but conditions the whole house quietly with hidden equipment. On this site's illustrative ranges, heating and cooling three rooms with separate wall splits might cost around $7,600–$11,000 installed, while a 14 kW ducted system with new ductwork in a single-storey house might cost around $12,000–$19,000. The better choice depends on how many rooms you actually use at once, your roof space, the climate and how long you plan to stay. This guide is part of the installation cost overview.
All prices are illustrative examples, not market rates.
How each system works
Split system. An indoor head (usually high on a wall, sometimes a floor console or ceiling cassette) connects through refrigerant pipes and a cable to an outdoor unit. Each head has its own remote. A multi-head split runs several indoor heads from one larger outdoor unit.
Ducted reverse cycle. A single indoor fan coil unit sits in the roof space or under the floor. Insulated flexible ducts carry air to ceiling or floor outlets in each room, and a return air grille draws air back. Motorised dampers divide the house into zones that can be switched on and off from a wall controller or app.
Both are heat pumps: they move heat from outside air into the house in winter and the reverse in summer, which is why efficient models deliver several units of heat for each unit of electricity.
Upfront cost compared
| Scenario (illustrative) | Wall splits | Ducted reverse cycle |
|---|---|---|
| One large living area only | One 7.1 kW split: about $3,200–$5,000 | Not usually worth it |
| Living area plus two bedrooms | 7.1 kW + 2 × 2.5 kW splits: about $7,600–$11,000 | 12–14 kW with 3 zones: about $10,500–$19,000 |
| Four-bedroom house, all rooms | 7.1 kW + 4 × 2.5 kW splits: about $12,000–$17,000 | 14–16 kW with 4 zones: about $12,000–$21,500 |
| Replacing an existing ducted gas system | Splits plus removing gas unit | Ducted unit re-using sound ductwork: about $8,500–$13,400 |
How the second row works: 7.1 × $350–$600 + $700 = $3,185–$4,960 for the living area. Each 2.5 kW bedroom split is smaller, so the fixed costs weigh more; at $600–$900 per kW plus $700 fixed, each costs about $2,200–$2,950. Total about $7,600–$10,900, and more with long pipe runs or a switchboard upgrade. The four-bedroom row adds two more 2.5 kW splits the same way. These are site assumptions, not quotes.
Small splits cost more per kW than large ones because the labour to mount a head, run pipe and connect power is similar regardless of size.
Running cost compared
Running cost depends on three things: how much heating or cooling you need, how efficiently the system delivers it, and your electricity tariff.
- Split systems condition only the room you are in. There are no duct losses, and modern inverter splits are among the most efficient appliances you can buy for a single room.
- Ducted systems lose some heat or coolth through ducts in the roof space, especially in summer when roof spaces can be very hot. They are most efficient when you run only the zones you need and the ducts are well insulated and sealed.
A practical rule: if you usually heat or cool one or two rooms at a time, splits will normally be cheaper to run. If the household is spread across the house for long periods, a well-designed zoned ducted system can be competitive. The running-cost guide shows how to estimate kWh and dollars, and the energy rating guide explains how to compare efficiency.
Other factors that matter
| Factor | Split systems | Ducted |
|---|---|---|
| Appearance | Visible head in each room; outdoor units on walls | Only vents and a controller visible; one outdoor unit |
| Noise inside | Fan noise in the room | Usually quieter at the outlet; noise depends on duct design |
| Outdoor space | One outdoor unit per split (fewer for multi-head) | One larger outdoor unit |
| Roof space needed | No | Yes, enough height for the unit and duct runs, or subfloor space |
| Failure | One unit failing affects one room | One unit failing affects the whole house |
| Replacement | Replace units one at a time as they age | Replace the main unit; ducts may last longer or need renewal |
| Renting or apartments | Often the only practical option | Usually needs a house with roof or subfloor access |
| Air filtration | Filters in each head | One return air filter for the whole system |
When each option tends to make sense
Splits are often the better fit when:
- you mainly use a living area and one or two bedrooms;
- the house has a low-pitched or cramped roof space;
- you want to spread the cost over several years;
- you live in an apartment or a strata building with rules on roof space.
Ducted is often the better fit when:
- you want even temperatures throughout a large house;
- you are renovating or building and can design duct runs and return air properly;
- you are replacing a ducted gas heater and the ductwork is in good condition and suitably sized;
- appearance and quietness inside matter more than upfront cost.
Questions to ask each installer
- What capacity have you chosen and how did you calculate it?
- How many zones, outlets and return air grilles are included (ducted)?
- What duct insulation R-value is specified?
- Where will the outdoor unit or units go, and how far are the pipe runs?
- Is a new circuit or switchboard work included?
- Are any NSW Energy Savings Scheme or Victorian Energy Upgrades discounts applied, and for which model?
Frequently asked questions
Is ducted air conditioning worth it for a small house?
In a small house where you only use one or two rooms at a time, splits usually give better value. Ducted becomes more attractive as the number of rooms you condition together grows.
Can I add cooling to my gas ducted heating?
Add-on cooling units exist, but many households now replace gas ducted heating with ducted reverse cycle, which both heats and cools. Ask the installer to check whether the ducts and return air suit cooling.
Are multi-head splits cheaper than several single splits?
Sometimes on outdoor space and installation, but not always on price. A single outdoor unit failure affects every head, and efficiency can be lower when only one head runs. Compare both on a written quote.
Do state discounts apply to ducted systems?
Some programs list eligible ducted models as well as splits, but rules and amounts differ by state and product. Check the eligible product list and ask for the discount on the quote.
Official sources
- energy.gov.au — household guidance on heating and cooling
- Energy Rating — energy rating labels and product registrations
- YourHome — Australian Government guide to energy-efficient homes
- NSW Climate and Energy Action — air conditioner upgrade incentive in NSW
- Essential Services Commission — Victorian Energy Upgrades
