Rebates & costs
How much does it cost to run an air conditioner?
Three numbers decide what an air conditioner costs to run: the power it draws, the hours it runs and the rate on your electricity bill. Your bill already has the third. The energy label and your own habits cover the other two.
6 min read
The formula
Spring replacement check
Free site visit and fixed quote on air conditioner replacements
From the first hot week in October our install calendar fills through to Christmas. Book before then and we will look at the old system, measure the room and give you a fixed quote for the new one, with the NSW Government discount included where the system qualifies.
For homes in our service area replacing an existing air conditioner. Book your visit by 30 November 2026.
Where to find each number
Your rate sits on your electricity bill, shown in cents per kWh. Energy Rating points to the service calculation section. On a time-of-use plan the afternoon peak rate costs more than the overnight one, which matters for a system doing most of its work from mid-afternoon.
For the hours and the power, look at the Zoned Energy Rating Label on the unit or in the brochure. It shows the estimated energy use each year in kWh for cooling and heating across hot, average and cold climate zones. Multiply the figure for your zone by your rate and you have a yearly running cost to compare between models. The federal Energy Rating Calculator works out your zone from your postcode.
Treat the label figure as a way of comparing models rather than a prediction of your bill. It assumes a set pattern of use, so someone who only switches on in a heatwave will use well under the label figure, while a household running the system most of the year will go over it.
What pushes the number up or down
The label gives you a starting point. Your own house and habits move it, mostly in these six ways.
| Factor | Effect on running cost |
|---|---|
| Thermostat setting | The NSW Government says every degree warmer in summer or cooler in winter can cut heating and cooling costs by 10%. It suggests 24 to 26°C in summer and 18 to 20°C in winter. |
| Star rating | A higher rating means less power for the same output. If two models match on stars and capacity, the one with the lower yearly kWh will cost less to run. |
| Age and condition | Blocked filters and dirty coils force the system to run longer for the same result. Older designs also start from a lower efficiency. |
| Sizing | Too small and the compressor never gets a rest on a hot day. Too big and it cycles on and off, which wastes power and leaves the room clammy. |
| The house | Ceiling insulation, blinds on west-facing glass and closed doors to unused rooms all shrink the load the system has to carry. |
| Your tariff | Peak, shoulder and off-peak rates can differ a lot. Pre-cooling the house before the peak starts moves some of the work into cheaper hours. |
Old system versus new
Settings and habits trim a running cost, but the system you run sets most of it. An old unit and a new efficient one can deliver the same cooling from very different amounts of power. The gap tends to widen as the old one ages.
The NSW Government puts a number on it. According to energy.nsw.gov.au, replacing an old system with an efficient reverse-cycle model saves $200 to $600 a year on energy bills. The older and harder-working the current unit, the closer to the top of that range a household lands.
Air conditioner running cost calculator
Compare what your aircon uses in a year with a new system the same size. Pick the size and how you use it, then add the figures from the unit's plate and the rate from your power bill. It covers one split system up to 9.5 kW, not ducted air conditioning.
Pick a size to see your estimate.
Where the numbers come from
The new-system figures are medians across the 1,872 reverse-cycle split systems up to 9.5 kW in the GEMS registry, for the label's average climate zone. They come from the Energy Rating data on data.gov.au as it stood on 21 September 2026. Hours of use follow the Zoned Energy Rating Label model, which works out the same as about 415 hours a year at full cooling output and 548 at full heating output. Your own system's efficiency comes from its plate.
Any saving shown leans low. A plate rating comes from a full-load test. Over a season an older fixed-speed unit does worse than that, because it keeps switching on and off.
Maintenance closes part of the gap between an old system and a new one. Cleaning the filters every few months keeps air moving through the coil. Learning how to clean an air conditioner filter takes about ten minutes. A system that still runs all afternoon without cooling the room has a fault rather than a dirty filter, which our post on an air conditioner not blowing cold air works through.
When a replacement pays its way
A system past ten years old that runs most days is the clearest case. The signs to look for, including the R22 gas deadline that makes some old units expensive to keep, are in how long air conditioners last.
Replacing an old system may also qualify for the NSW Government's upfront discount, which comes straight off the quote. Our NSW air conditioning rebate page sets out the eligibility rules. When you are ready to price it, our air conditioner replacement service includes a site visit and a fixed quote with the discount included where the new system qualifies. For a first system in a room that never had one, start with split system air conditioning.
Common questions
- How much does an air conditioner cost to run per hour?
- Multiply the power the system draws in kilowatts by your electricity rate per kWh. A small split system often draws well under 1 kW at full output, so an hour costs less than one kWh at your rate. Once the room reaches temperature an inverter system slows down and draws less again.
- Is it cheaper to leave the air conditioner on all day?
- For a full day out, switching off saves more. For an hour or two the gap is small, because a system pulling a hot house back down runs at full power until it catches up. A timer that starts the system half an hour before you get home gets you most of the comfort for less.
- Does heating cost more than cooling?
- Over a year it often does in NSW, because a reverse-cycle system spends more hours heating. The Energy Rating label assumes 1,921 hours of heating against 840 hours of cooling a year for its average climate zone, which it models on Richmond, northwest of Sydney.