Large air conditioners buying guide: How to find the best aircon

What size air conditioner is right for me?

A large air conditioner generally provides over 6 kilowatts (kW) of cooling capacity. It's important to check what kW capacity is ideal for your room size and how much it will cost you, to figure out whether it's necessary.

To figure out the best aircon model for you, compare kilowatt capacity (kW) against room size and type:

For the most accurate measurement, you need to account for a number of factors, including:

• Size. Height, length and width.
• Type. Is it a bedroom, living room, dining room or kitchen etc? A kitchen, for example, may need extra cooling if you cook often.
• Windows and glass doors. The size and position, e.g. a big north- or west-facing window collects much more heat in summer and will need a more powerful aircon.
• Window curtains/shading. This coverage will counteract heat from the sun.
• Insulation. The insulation level of walls, floor and ceiling will reduce the need for extra heating in winter.
• Climate. Consider the local climate in your area. For example, a place in Brisbane will require a more powerful aircon than an identical home in Sydney; if you live in Western Sydney, temperatures will generally be hotter than locations closer to the city on the same day.

You can try plugging your measurements into this capacity calculator from the Australian Institute of Refrigeration, Air Conditioning and Heating for a quick calculation.

How much does it cost to run an air conditioner?

Depending on the specific AC model, your annual running costs could vary by several hundred dollars. The following running costs per year are only an estimate and may differ depending on your usage and energy prices.

Read our full cost guide

Large air conditioner types

There are five main types of air conditioners: split-system, multi-split, ducted, wall/window and portable.

There are also specific aircon categories, including reverse cycle and inverter/non-inverter types.

• Reverse cycle aircon
  • Can warm as well as cool
  • A cheaper way to warm your home in winter
  • Costs more than cooling-only aircon
• Inverter vs non-inverter aircon
  • Inverter. Regulates the speed of the compressor so it can speed up/down depending on usage and doesn't need to stop/start throughout the day, saving energy.
    • More efficient
    • Costs less to run
    • Split system models are usually inverter type
  • Non-inverter. Compressor is either on full power or off, creating extra wear and tear and using more power on each start-up.
    • Uses more electricity
    • Cheaper to buy, but costs more to run
    • Not as commonly sold

How to compare large air conditioners

A large air conditioner could cost you from around $1,390 to over $5,000, depending on the brand, model and range of features.

Here are the other key features you should consider:

Fan speed

The fan pushes hot/cool air throughout the room. To minimise noise and draught, pick a model with a large airflow range and multiple fan speeds.

Operating modes

As well as cool and dry modes found on most aircons (and heat modes on reverse cycle models), some aircons offer fan only, auto and eco modes.

• Fan only. Circulates air without heat, cool or dry functions when you just want a pleasant breeze.
• Auto. Automatically selects the mode needed to maintain your target temperature.
• Eco. Conserves energy by either adjusting the cooling/heating output by 1-2 degrees or utilising sensors to detect when no one is in the room and then lowering output accordingly.

Operating range

Most aircons have an operating range of -10 to 45 degrees Celsius, which should suit most areas in Australia. If you live in an area that is extremely hot and dry, an evaporative cooler could be a cheaper option for your home. Also check out our renovation tips to beat the summer heat, so you can maximise the cool in your home.

Wall-mounted vs ceiling-mounted

The right mount type for you depends on your room type.

• High wall. Mounted high on the wall for easy airflow circulation
• Floor-mounted. A floor level mount may be more suitable for those who want easier, convenient access to the AC
• Cassette. Mounted to the ceiling
• Floor/ceiling. Gives you the option of mounting to either the floor or ceiling

Human presence sensor

Detects when people are in the room, so that the system knows to keep running – some will even shift airflow towards the person – and when to shut off when no one is around, to save energy.

Wi-Fi and smartphone connectivity

Some recent models can connect to your home Wi-Fi for remote control via your smartphone, which is handy for pre-cooling your home while you're at work, or if you misplace the remote.

Air filtration

Many air filter systems claim to eliminate allergens, bacteria, dust, mould and odours from the air. If anyone in your household has allergies, asthma or sensitive skin, opt for a filter that's labelled anti-allergen. Some filters also include a self-cleaning feature to keep the aircon interior dry and minimise dust build-up and mould growth.

Additional factors to think about:

Remote control

Better designs will have big, well-spaced buttons with labels that are easy to read and a large LCD screen.

Sleep mode

This gradually adjusts the temperature when sleeping so that the aircon is quieter and doesn't use as much energy (you don't need the room to be as cold during sleep, especially in the early morning).

Demand Response Enabling Device (DRED)

If your energy provider offers the PeakSmart service (mandatory in Queensland), you can pick a model that either includes built-in DRED or offers DRED as an add-on. During peak electricity usage periods, your aircon will remotely switch to an economy mode to reduce your power usage and energy costs. However, this is only available with a few companies in specific states.

Auto de-icing

For those who live in cold regions, opt for an AC with auto de-icing to prevent frost build-up during winter on the outdoor heat exchanger coils.

Noise level

Split-system aircons are generally super quiet both indoors and outdoors; however, you should test a model's noise level before purchasing. A loud indoor unit could affect your sleep, conversation and activities, while a loud outdoor unit that's near your bedroom/living room could disturb you and your neighbours. Before buying, check local council and strata (if you're living in a unit) restrictions on specific aircon noise levels.

Refrigerant gas

Ozone-depleting refrigerants are harmful to the environment and your health.

• Chlorofluorocarbons (CFCs) are not commonly used in ACs nowadays.
• Hydrofluorocarbon (HFC) is the most common type of refrigerant that's still used in ACs; however, this should be phased out in the next several decades. Of HFCs used in most household aircons, R32 is becoming increasingly popular over R410A, as it's more energy-efficient and potentially contributes less to global warming.