How much does it cost to run an air conditioner?

A common assumption made by many Australians is that air conditioners cost a lot of money to run.

You may be surprised at the cost of running an air conditioner, it's actually significantly lower than many would assume. That being said, the fact is that running an air conditioner does raise energy bills and undeniably costs the user money.

Here, we detail the running costs of operating an air conditioner, what you can do to save money on AC costs and take a look at some questions commonly associated with the cost of running an air conditioner.

Cost breakdown for running split system air conditioners

While there are a number of factors that affect the cost of running an air conditioner - the size of the area being cooled and the capacity of the air conditioner itself are the two factors that have the most significant impact on costs.

The size of the room will determine how long the air conditioner will need to run in order to adequately cool it to the desired temperature. The length of time the air conditioner is on directly impacts the costs of running it.

The capacity of the air conditioner also directly correlates to the amount of electricity it consumes whilst running. Air conditioners with higher capacity cost more to run per hour when they are utilising that capacity than smaller systems.

If you have an air conditioner that has insufficient capacity to cool the space you have then it will be running at capacity most of the time - this will lead to premature wear on the system.

If you have an air conditioner that has excess capacity for the space you are cooling - you will have invested too much in your air conditioner and if it is extremely oversized then the system will be constantly cycling on and off - which is also leads to premature wear.

The cost of each kW hour of electricity your air conditioner consumes is determined by your electricity retailers tariff - unless you are lucky enough to be using electricity you have generated yourself from Solar.

Another factor that affects the costs of running an air conditioner - that many Aussies aren't aware of - is where in the country you are located. Australia doesn't have blanket costs for energy across the country - each state has varying costs as each state has different electricity retailers.

Below are the average costs per kW per state:

  • NSW - 26.53 cents
  • VIC - 25.86 cents
  • QLD - 22.20 cents
  • SA - 35.32 cents
  • ACT - 22.81 cents
  • TAS - 26.59 cents

In order to calculate the cost of running your air conditioning system, you'll need to figure out how many watts you're using. If you have the measurements for the area you want to cool, you can figure out how many kW of capacity are required by heading to our guide here and using the calculation equation. [insert hyperlink - WHAT SIZE AIR CONDITIONER DO I NEED]

Alternatively, if you already know the kilowattage of your air conditioning unit, you can go ahead and use the below equation to figure out the approximate cost of running your air conditioner.

This equation will help you figure out the cost per hour of running your air conditioner.

(kW (capacity of unit) / EER (Energy Efficiency Rating -published by the air conditioners manufacturer) x price/ hour (based on the electricty retailer in your state) = cost to run per hour (price/ kWh)

As an example:

(2.5kW Capacity / Energy Conversion Factor 4.5) x $0.28 per kWh = $0.15 per hour

We've also taken the hard work out for you by putting together the average costs to run different sizes of air conditioners in the table below based on an AC that is run eight hours a day in QLD (current energy tariff's in Qld are around $0.28 per kW hour.

Air conditioning costs for a small room

A room 10m2 - 20m2 will require a 2.5 kW unit to cool the room.

  • Hourly cost: $0.15
  • Daily cost (8 hours per day): $1.20

Air conditioning costs for a medium room

A room 20m2 to 30m2 using a 3.5 kW unit to cool the room.

  • Hourly cost: $0.25
  • Daily cost (8 hours per day): $2.00

Air conditioning costs for a large room

A room 30m2 to 45m2 using a 6.0 kW unit to cool the room.

  • Hourly cost: $0.50
  • Daily cost (8 hours per day): $4.00

Air conditioning costs for an extra-large room

A room 45m2 - 65m2 using an 8.0 kW unit to cool the room.

  • Hourly cost: $0.68
  • Daily cost (8 hours per day): $5.44

Cost breakdown for running ducted air conditioners

The cost of running a ducted air conditioner is worked out in the same way as a split system, however, the air conditioners capacity is normally larger and you may not be using all of the system's capacity all the time.

However, below is an approximate guide to the costs involved with running ducted air conditioning - assumes a 16kW system - which is a medium / large sized system.

(16.0 kW Capacity / Energy Conversion Factor 3.45) x $0.28 per kWh = $1.29 per hour

A 16.0kW air conditioner has enough capacity to cool 95 square metres of space down to 24 degrees

  • 2 hours per day: $2.58
  • 4 hours per day: $5.16
  • 6 hours per day: $7.74
  • 8 hours per day: $10.32
  • 12 hours per day: $30.96
  • 24 hours per day: $61.92

Tips to lower the costs of running an air conditioner

Increase the temperature set point of your air conditioner

The air conditioners temperature set point, is the factor most easily changed, that has the biggest impact on the energy used by your air conditioner.

Each degree you raise the air conditioners temperature set point reduces your energy consumption by approximately 10%. So a set point of 25 degrees uses 10% less energy than a set point of 24 degrees.

Engage the auto mode on your thermostat

One feature that's often underutilised and can save a significant amount of money on your electricity bills is setting your air conditioning to 'auto' mode.

If your fan setting is set to the high, constant mode, the fan will continue to run even when the desired temperature is reached. The fan works independently of what the thermostat says unless it's set to 'auto'.

If a thermostat is set to auto, the air conditioning will work in conjunction with the fan to reach the set temperature. Once this temperature is reached, both the fan and the air conditioning will go into an idle mode until the temperature rises higher than what's set on the thermostat.

By engaging the 'auto' function, your air conditioner and fan will only run when it's required, this will result in lower electricity bills and a longer life span for your unit. You'll also enjoy the added benefit of having to change the filter less frequently, as less air is filtered through it.

Set a timer on your thermostat

For a lot of people, rugging up in a thick doona in an icy cold room is thoroughly enjoyable. However, your air conditioning doesn't need to stay on all night for you to enjoy a cool night's sleep. If you use the timing set on your thermostat, you can enjoy lower energy bills AND a cool night's sleep.

Most thermostats will have a different way or button to set the time function. So, it's best to consult your manual to check how to set yours.

Use the smart function of your thermostat or remote

Many newer models of air conditioning have smart functions. One of these smart functions can give you the ability to access and control your air con from afar. Some systems have phone apps that allow you to control your system like a normal remote.

This app is really handy for people who love coming home to a cool house. Rather than leaving your air conditioning on all day while you're out and sending your energy costs through the roof (quite literally), you'll be able to switch on your air conditioning half an hour before you head home.

Use a fan in conjunction with your air conditioner

When you already have an air conditioner installed, a fan may seem moot. However, fans can actually help the cold air from an air conditioner circulate around, resulting in lower electricity bills. Fans are significantly cheaper to run than air conditioning - on average a ceiling fan runs at about 30 watts an hour - so this means they cost less than a cent an hour to run.

FAQ

Does turning an air conditioner on and off cost more than leaving it running?

A common question is whether turning an air conditioner on and off a lot costs extra due to the powering up and powering down activity. This is comparable to an iPhone - when you turn an iPhone on and off a lot the battery tends to drop faster than just keeping it on because of the extra battery needed to start it up and shut it down.

While this theory may make sense in a way - it's not really correct. Turning an air conditioner on and off throughout the day will use much less energy than leaving it on for an entire day. Yes, turning an air conditioning on does use slightly more energy than it's uses when it's already running. However, the energy it takes to turn on the system is so small that it would barely have an impact on your electricity bill - especially compared to the electricity cost of running an AC all day long.

Aside from power costs, what other costs are involved with running an air conditioner for long periods of time?

Two things that will be significantly affected by extensive air conditioning use are the life span of your air conditioning, as well as the filters. An air conditioner that is consistently used will not last as long as an AC system that is sparingly switched on.

Filters, on the other head, are a cheap and easy fix if you know what you're doing. But, if you don't change your filters when it's required, it can cause a host of other problems in your system which may come at a costly fix. AC filters pull dirt and debris out of your air conditioning system. If the filter isn't regularly changed, dirt can build up in the filter and your air conditioner's air pathways can be clogged.

It is recommended to clean your air filter every ninety days. Although replacing an air filter may sound straightforward, there are many different styles, types and sizes of air filters on the market. If you're not sure how to change a filter, a technician can come over and quickly and easily change the air filter for you for a small cost.

How does the EER energy rating affect air conditioning cost?

EER stands for energy efficiency ratio. This shows the ratio between the cooling achieved and the energy it takes to do so. So, the higher the number is on your air conditioner for EER (energy efficiency ratio), the more energy-efficient the unit is. The more energy efficient a unit is, the less energy you'll end up using and you'll save more money on your electricity bill. 12 is considered an excellent EER rating, and your AC system should be very efficient at using minimal energy if this rating is awarded.

Ready for a quote?

If you're interested in installing an air conditioning system, fixing your current one or would just like some more information about your options, get in touch with our friendly team for a quote or to schedule an at home inspection.

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