How much does it cost to run my air conditioner in the summer?

Running a reverse cycle air conditioning system can cost anywhere from $0.20–$0.70 per hour, depending on the size of the space they're cooling. A small system will probably cost less than $0.35 per hour to run.

We've done a detailed cost breakdown of how much running your aircon might cost you based on its size and where you live.

How much does air conditioning cost to run?

5–6kW$273 (1,258kWh)$104 (420kWh)$60 (265kWh)

_{Note: These values are consumption figures based on reverse cycle, single split system, non-ducted Daikin air conditioner products registered in the Commonwealth of Australia E3 database. Capacity is based on ratings at 35°C. Usage estimates are based on average power costs: 21.68c/kWh in Brisbane, 24.68c/kWh in Sydney and 22.6c/kWh in Canberra. Climate zones are defined by the new Energy Label rating system for air conditioners introduced for products registered after 1 April 2020.}

What affects the running cost of my air conditioner?

Air conditioners work primarily by pulling heat out of your house and dumping it outside. Here's what impacts how much power your aircon consumes to do its job:

• Outside temperature. The larger the temperature gap between indoors and outdoors, the less efficient your air conditioner runs. It's harder to cool your house down when it's a blazing 35°C day in Brisbane than when it's a more temperate 25°C in Hobart.
• Target temperature. Each extra degree of cooling forces your aircon to work harder. Dropping the thermostat by a single degree can bump up your running costs by 10%.
• The area you're cooling. Larger rooms have more air to cool and takes more energy. If your room is north- or west-facing with windows, it could let in extra heat during summer and make cooling more difficult.
• The aircon unit. A large aircon unit (3kW and up) chews through a ton of energy in an hour compared to a smaller one. Also, some air conditioners are simply more energy efficient, reducing costs.

We'll cover these in more detail in the following sections.

What's the best temperature to set my aircon?

What size air conditioner do I need?

Larger areas need more powerful air conditioning units.

While you want to make sure that your aircon is big enough for the job, it's extremely important not to oversize it. An oversized aircon will cool down a small space very quickly and then shut off, causing a few problems:

• Aircons gradually remove humidity from the air while operating. An aircon that switches off too fast will lower the temperature but not the humidity, leaving you uncomfortable.
• This on-off on-off operation will create big variations in temperature throughout the day, especially in the afternoon.
• Constantly switching on and off creates wear and tear and shortens the unit's effective lifespan.

With that in mind, here's a rough guide to size:

How do the best air conditioners compare in terms of running costs?

These are how some of the top air conditioners compare regarding running costs:

_{Note: Operating cost was calculated using data from the Commonwealth of Australia E3 product database assuming Sydney's climate and usage rates of 24.68c/kWh. Cooling capacity is based on an outside temperature of 35°C.}

Reverse cycle vs ducted air conditioning: What are the main differences?

Reverse cycle (also known as split cycle or split system) air conditioners and ducted systems are designed for different purposes. Here's how they compare on a few major points.

What type of air conditioner is the cheapest to run?

The cheaper option depends on what you're trying to achieve with your aircon system.

• If you want to cool your whole house, a ducted system will be cheaper to run than multiple split system air conditioners for each room.
• If you want to cool some parts of your house, having a couple of split systems to cool key rooms or living spaces will be cheaper, especially since you likely won't be running them as often as a ducted system.

However, if your house was built without air ducts or if you're renting, ducted air conditioning may not be a practical or affordable option.

How much can you save on air conditioning costs by switching energy plans?

Changing your energy plan to one with lower usage costs can certainly save you money on cooling costs, but it's less than you might think.

Here are 2 case studies – a Canberran household and 1 in Brisbane.

Case 1: Canberra (cold climate)
A resident of Canberra with a 4kW aircon will use about 181kWh of electricity on cooling per year. At 181kWh of power use multiplied by 22.6c per kWh on usage rates, this costs $41 per year.

Now, say they switch to a new energy plan that only charges 21.6c per kWh for power.

Over the year, at 181kWh of power use multiplied by 21.6c per kWh on usage rates, they'll now spend $39 on cooling, saving them $2.

Case 2: Brisbane (hot climate)
A resident of Brisbane with a 4kW aircon uses about 864kWh of power on cooling annually. This costs $187 a year on 864kWh of power use multiplied by 21.68c per kWh on usage rates.

Next year, they switch to an energy plan that only charges 20.68c/kWh for energy.

With the new plan, they'll spend $179 a year on cooling and save $8. This is at 864kWh of power use multiplied by 20.68c per kWh on usage rates.

While this doesn't seem like much, remember that you'll be shaving small amounts off all your power use with a cheaper energy plan, meaning that switching energy plans is still worthwhile.

Tips on how to save energy while using an air conditioner this summer

• Clean the filters regularly. It's recommended that you clean your air conditioner's filters at least once a year. Filters can become clogged with dust, pollen or even mould, lowering their efficiency.
• Raise the thermostat. Setting the right target temperature is vital. Each extra degree of cooling can add 10% to your bill.
• Use your aircon for fewer hours. Running your aircon only during the hottest parts of the day – say, cutting down from 4 to 3 hours of use – will knock 25% off your cooling bill.
• Use fans to circulate air. If you only need some light or localised cooling, such as a small room or a desk, use a fan. They work nearly as well as an aircon for a fraction of the cost.
• Close doors, windows and blinds. If you stop heat from getting in, you'll have a much easier time keeping your living spaces cool. If there's a cool breeze, you might want to open your windows instead.