Ducted air conditioning running cost
By Sithum Imarsha Last reviewed
A typical 14 kW ducted in the Average climate zone uses about 3,561 kWh of energy a year on its label, about $1,140 at 32c/kWh. Flat out it costs about $1.34 an hour to cool, and a typical hour is nearer $0.47.
Your result
Yearly cost from the label
$1,140a year
3,561 kWh × 32c/kWh
14 kW ducted, Average zone (suggested default)
- Cooling a year
- $432
- Per hour, flat out
- $1.34
- Per typical hour
- $0.47
- Heating a year
- $707
- Per hour, flat out
- $1.34
- Per typical hour
- $0.36
Two methods, side by side. The yearly cost uses the label. The per-hour figures use rated input. A typical hour is our estimate.
Tip. Each degree cooler in summer or warmer in winter adds about 5–10% to energy use. Try 25–27 °C in summer and 18–20 °C in winter.
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How we calculated this
- The yearly cost is the kWh on the Zoned Energy Rating Label for the climate zone, times the electricity rate.
- The cost per hour flat out is the rated input in kW times the rate.
- A typical hour costs less, because an inverter slows down once the room is at temperature. That part is an estimate.
Full method, tables and sources: Air conditioner running cost calculator
Read the label kWh for your zone
Cooling 1,351 kWh · Heating 2,210 kWh · Total 3,561 kWh (Average zone, registry median)
Multiply by your rate
3,561 kWh × 32c/kWh = $1,140 a year
Cost per hour, flat out
Cooling: 4.18 kW × 32c/kWh = $1.34. Heating: 4.2 kW × 32c/kWh = $1.34.
Cost per typical hour (Estimate)
Cooling: $1.34 × 35% = $0.47. Heating: $1.34 × 27% = $0.36.
| Size | Label kWh a year | Cost a year |
|---|---|---|
| 2.5 kW split | 538 | $172 |
| 3.5 kW split | 701 | $224 |
| 5 kW split | 1,102 | $353 |
| 7.1 kW split | 1,597 | $511 |
| 8 kW split | 1,853 | $593 |
| 10 kW split | 2,319 | $742 |
| 10 kW ducted | 2,455 | $786 |
| 12.5 kW ducted | 3,102 | $993 |
| 14 kW ducted | 3,561 | $1,140 |
| 16 kW ducted | 4,100 | $1,312 |
| 18 kW ducted | 4,930 | $1,578 |
| 20 kW ducted | 5,484 | $1,755 |
This version starts with a typical 14 kW ducted system. Pick your size from 10 to 20 kW. Every size is the median of the models on the Energy Rating registry.
Ducted systems: what is different
Not yet checked
- Ducted systems do not have to show an energy label. Units under 30 kW may show one, and all of them must register their seasonal efficiency. If yours has no label, the per-hour figures from its rated input are the better guide. (GEMS Regulator, questions and answers on the zoned label, Q2)
Official source
- The median 10 kW ducted unit on the registry has 2.5 cooling stars in the Average zone, against 3 for a 10 kW split. Its label shows 910 cooling kWh a year against 851 for the split, about 7% more. (Energy Rating registry ac_2026_09_17.csv, deduplicated medians)
- Set 25–27 °C in summer and 18–20 °C in winter. (YourHome, heating and cooling)
| Size | Hot zone | Average zone | Cold zone | An hour of cooling |
|---|---|---|---|---|
| 10 kW ducted | $924 | $786 | $1,551 | $0.95 |
| 12.5 kW ducted | $1,201 | $993 | $1,920 | $1.18 |
| 14 kW ducted | $1,349 | $1,140 | $2,189 | $1.34 |
| 16 kW ducted | $1,542 | $1,312 | $2,526 | $1.55 |
| 18 kW ducted | $1,899 | $1,578 | $2,931 | $1.80 |
| 20 kW ducted | $2,223 | $1,755 | $3,220 | $1.96 |
- In every row the Cold zone (Canberra, Hobart and Melbourne) costs the most and the Average zone (Adelaide, Perth and Sydney) the least: $2,189 against $1,140 a year for the 14 kW ducted.
- 10 kW is the one size our list has as both kinds. In the Average zone the 10 kW ducted costs $786 a year and the 10 kW split $742: $44 more for the ducted system.
- The 20 kW ducted has 2 times the cooling capacity of the 10 kW ducted and costs 2.23 times as much a year in the Average zone: $1,755 against $786. So the bigger system costs more to run for each kW of capacity.
Each row is the median of the ducted models of that size on the Energy Rating registry (Official source), run through the calculator on this page. The rate is 32c/kWh, our plain average of the state default rates: Dated third-party source, except Western Australia (Official source). The zones are the three on the energy label (Official source). Hot: Brisbane and Darwin. Average: Adelaide, Perth and Sydney. Cold: Canberra, Hobart and Melbourne. An hour flat out is an hour at the rated cooling input, times the rate. It is not a typical hour, and our data holds no figure for the most a unit can draw.
Ducted systems on the registry
What a ducted system moves for what it draws
The median 14 kW ducted system on the registry moves 14 kW of heat out for a rated input of 4.18 kW when cooling, and puts 16 kW in for 4.2 kW when heating.
Source: Energy Rating registry ac_2026_09_17.csv (data.gov.au), medians of deduplicated available models (Official source). Checked 1 October 2026.
That is 3.35 kW of cooling and 3.81 kW of heating for each kW of power. At 10 kW, the one size our list has as both kinds, the ducted system gets less cooling from each kW than the split: 3.36 kW against 3.69 kW.
An inverter at half capacity
On the registry's half-capacity test a median unit at 50% capacity draws 37% of its rated input.
Source: Registry half-capacity test points (ac_2026_09_17.csv), median of 2,328 models (Official source). Checked 1 October 2026.
For the 14 kW ducted system that is about 1.55 kW when cooling: $0.49 an hour at 32c/kWh, against $1.34 flat out. The table above shows the flat out figure: an hour at the rated input.
How many models each row rests on
Models behind each median, after removing repeats: 110 at 10 kW, 111 at 12.5 kW, 97 at 14 kW, 51 at 16 kW, 34 at 18 kW and 26 at 20 kW.
Source: Energy Rating registry ac_2026_09_17.csv (data.gov.au), medians of deduplicated available models (Official source). Checked 1 October 2026.
The 20 kW ducted row rests on the fewest models: 26, against 110 at 10 kW. Type the kWh from your own label, or the rated input from the nameplate, and the calculator uses those in place of the median.
New to the label method? Read the full guide on the main air conditioner running cost calculator.