Ducted Air Conditioning Running Cost Calculator
Ducted air conditioning is cheap to ignore and expensive to run badly. Enter your system capacity, how you use it and your electricity rate to estimate the annual running cost, plus an indicative five-year figure.
Check the outdoor unit compliance plate. Most Australian homes run 10kW to 18kW ducted.
Use the usage rate on your bill, not the daily supply charge.
Ducted systems draw far more power at start-up and while pulling a hot house down to setpoint than while holding it there. Running a shorter, steadier schedule beats switching the system off completely and then blasting it cold when you get home.
- Compressor (cooling and heating)$350
- Fan and air handler$100
- Standby and controls$50
💰 Ways to save
- Use the zoning you already paid for. Most ducted installs include four to eight motorised zones and most households leave them all open out of habit. Conditioning the living zone during the day and the bedroom zone at night, rather than the whole floor plan, is the single largest saving available and costs nothing to implement.
- Move the thermostat to 24°C in summer and 20°C in winter. Every degree closer to the outdoor temperature cuts consumption by roughly 5 to 10 per cent, so shifting a habitual 20°C summer setpoint up to 24°C can reduce the cooling half of your bill by a third with almost no perceptible loss of comfort once the humidity is under control.
- Get the ducts pressure tested if the system is more than ten years old. Flexible duct in a hot roof cavity degrades, joins pull apart at the collars and insulation compresses, and a leaking run can dump a meaningful share of your conditioned air into the roof. Testing and resealing typically costs a few hundred dollars against hundreds a year in waste.
- If you have rooftop solar, shift the heavy lifting into daylight. Pre-cooling the house between 11am and 3pm on generation you would otherwise export at 5 to 8c/kWh, then coasting through the evening peak, changes the effective rate you pay for comfort more than any efficiency upgrade you can buy.
How we estimate this
## What ducted air conditioning actually costs to run
Pricing reviewed: June 2026.
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Pricing reviewed June 2026. Indicative Australian costs, not a quote.
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Understanding ducted air conditioning running costs in Australia
What ducted air conditioning actually costs to run
A typical Australian ducted system of 12kW to 16kW cooling capacity costs somewhere between $400 and $1,400 a year to run, and the spread inside that range is driven almost entirely by behaviour rather than by the machine. As a working figure, a 14kW inverter system drawing around 4kW of electrical input at full load and running six hours a day across a four to five month season at 33c/kWh lands near $450 to $600 a year. Push that to ten hours a day, add winter heating and drop the thermostat to 19°C, and the same hardware comfortably passes $1,500. This is why running cost, not purchase price, is the number worth modelling before you commit to ducted over multiple split systems.
Electricity tariffs by state in 2026
The rate you pay is the second biggest lever and it varies widely across the country. In 2026 typical residential usage rates sit near 25 to 28c/kWh in the Northern Territory and parts of Tasmania and Western Australia, around 28 to 32c/kWh in Victoria and Queensland, roughly 35 to 40c/kWh across much of New South Wales, and 42 to 46c/kWh in South Australia, which remains the most expensive mainland market. Time-of-use plans complicate this further: a peak window that runs from 3pm to 9pm captures exactly the hours most households want cooling, and peak rates on those plans can be 45 to 55c/kWh while the off-peak overnight rate might be 18c. Read the usage rate off your bill rather than assuming, because a household on a flat 33c plan and one on a peak-heavy time-of-use plan can pay very different amounts for identical comfort.
Why zoning is the biggest saving available
Almost every ducted system installed in the last fifteen years has motorised zone dampers, and most households never learn to use them. Conditioning eight zones when two are occupied means the compressor is working to hold temperature in empty bedrooms all evening. Closing down to the zones you are actually in typically reduces consumption by 25 to 40 per cent, and it also lets the system operate closer to its efficient part-load band rather than cycling. There is a limit: most ducted units require a minimum airflow, so closing too many zones forces air through a bypass and wastes energy differently. The practical rule is to keep at least a third of the total airflow open, which usually means two or three zones rather than one.
Setpoint, humidity and the degree rule
Each degree you move the thermostat away from the outdoor temperature changes consumption by roughly 5 to 10 per cent. Setting 18°C on a 38°C day is not just expensive, it often overshoots what the body actually needs, because comfort at high humidity is driven as much by moisture removal as by dry bulb temperature. A system running steadily at 24°C removes humidity across a longer cycle and frequently feels better than one blasting to 19°C and cutting out. In heating mode the same logic applies in reverse: 20°C is comfortable for most households and every degree above that adds materially to the winter half of the bill.
Ducts, insulation and the roof cavity problem
The distribution system quietly determines how much of what you pay for actually reaches the room. Flexible duct sitting in a roof cavity that reaches 55°C or more on a summer afternoon relies entirely on its insulation wrap, and that wrap compresses, tears and sags over time. Joins at collars and branch takeoffs pull loose. A system with meaningful duct leakage is paying to cool the roof space, and the symptom is usually a room at the end of a run that never quite reaches setpoint no matter what the controller says. A duct pressure test, resealing and re-supporting sagging runs typically costs a few hundred dollars and is the highest return maintenance item on a ducted system after filter cleaning.
Ducted against splits on running cost
For a household that genuinely conditions the whole home, ducted is efficient and comfortable. For a household that spends most of its time in two rooms, multiple split systems usually win on running cost by a wide margin, because each unit only ever conditions the space it serves and there are no duct losses at all. The crossover point in practice sits around three to four regularly occupied rooms. If you already have ducted, the way to close that gap is aggressive zoning, a sensible setpoint and a solar-aligned schedule. Use the annual estimate above as a baseline, then check it against your own bill by comparing a summer quarter with a shoulder quarter, which isolates the air conditioning share reasonably well.
Frequently asked questions
How much does ducted air conditioning cost to run per hour in Australia?
A 14kW ducted system typically draws around 3.5 to 4.5kW of electrical input at full load, so at a national mid-point rate of 33c/kWh it costs roughly $1.15 to $1.50 an hour running hard. Once the house reaches setpoint the inverter modulates down and the real-world average is usually closer to 60 to 70c an hour.
What does ducted air conditioning cost per year?
Most Australian households land between $400 and $1,400 a year. A 14kW system run six hours a day across a four to five month season at 33c/kWh sits near $450 to $600. Year-round use, a low setpoint and running every zone can take the same system past $1,500.
Does using zones actually save money?
Yes, and it is the largest single saving available. Conditioning two or three occupied zones instead of the whole house typically cuts consumption by 25 to 40 per cent. Keep at least a third of the total airflow open, because closing too many zones forces air through the bypass and undoes part of the saving.
How much does each degree on the thermostat cost?
Roughly 5 to 10 per cent of consumption per degree. Moving a summer setpoint from 20°C to 24°C can cut the cooling portion of the bill by around a third, and holding 20°C rather than 23°C in winter produces a similar saving on the heating side.
Is ducted more expensive to run than split systems?
For a household that only uses two or three rooms regularly, yes, usually by a wide margin, because ducted conditions a larger volume and loses some conditioned air to duct leakage. For homes that genuinely condition the whole floor plan the gap narrows and comfort is better. The crossover sits around three to four regularly occupied rooms.
Do electricity rates vary much by state?
Considerably. In 2026 typical usage rates run about 25 to 28c/kWh in the Northern Territory and parts of Tasmania and Western Australia, 28 to 32c/kWh in Victoria and Queensland, 35 to 40c/kWh across much of New South Wales, and 42 to 46c/kWh in South Australia. Time-of-use plans can push the 3pm to 9pm peak above 50c/kWh.
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