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Air Conditioning in Australia: How to Choose the Right Unit for Your Home or Business – A Sizing Guide

An air conditioner size calculator and an HVAC specialist can make sizing an air conditioner unit for a home or business in Australia easier. Measure your space to determine the right air conditioner size. Multiplying the room’s length and width provides the square metres.

After measuring the square metres, consider how many people will use the room and other characteristics that may affect cooling, such as large windows or high ceilings. These factors affect the space’s cooling needs, thus they must be considered while choosing an air conditioner.

Climate is another important element in air conditioner sizing. Australia has many climates, so it’s important to choose an air conditioner that suits yours. In a hot and humid area, you need a unit that can handle high humidity where as ducted evaporative air conditioners are suitable for dry climates.

Air conditioner sizing calculators help you choose the right unit. These calculators consider square metres, persons, and weather. They use algorithms and data analysis to determine how much cooling capacity your area needs, taking into account insulation levels, window and door counts, solar exposure, and room orientation.

These calculators use basic concepts and may not account for your home or business’s layout or other unique elements. Thus, to choose the right air conditioner, speak with an HVAC professional. An HVAC expert may assess your area and recommend the best air conditioning device.

You can find a useful air conditioning calculator here:

General Guidelines

Here are some general guidelines for air conditioner sizes based on room square meterage:

  • Rooms up to 20 square meters: A 2.5kW to 3.5kW wall-mounted split system; Price Guide: $1,500 – $3,000 +
  • Rooms between 20-30 square meters: A 3.5kW to 5kW wall-mounted split system; Price Guide: $1,800 – $3,500 +
  • Rooms between 30-40 square meters: A 5kW to 7.1kW wall-mounted split system; Price Guide: $3,000 – $4,500 +
  • Rooms between 40-50 square meters: A 7.1kW to 9kW wall-mounted split system; Price Guide: $3,000 – $5,500 +
  • Rooms larger than 50 square meters: A 9kW or larger wall-mounted split system; Price Guide: $4,000 – $10,000 +

It’s important to note that these are just general guidelines and it’s always best to consult with an HVAC professional to determine the right size air conditioner unit for your specific space and needs. The climate, number of people, room layout, and other factors such as window size and sun exposure, can also impact the size of the unit that is needed.


In conclusion, using an air conditioner sizing calculator and talking with an HVAC specialist can make sizing an Australian air conditioner unit easy. Consider the square metres of your room, the number of people who will use it, and the weather in your location to make sure your air conditioner can chill your space without overworking. When in doubt, consult a professional and make sure your air conditioner is the proper size for your home or company.

In a Nutshell

  • To size an air conditioner unit for a home or business in Australia, use an air conditioner size calculator and consult with an HVAC specialist.
  • Factors to consider include the square footage of the space, the number of people using the room, and the climate in the area.
  • Climate is particularly important in Australia due to its varied regions, with hot and humid areas requiring units that can handle high humidity, while dry climates are better suited for ducted evaporative air conditioners.
  • Air conditioner sizing calculators use algorithms and data analysis to determine the needed cooling capacity, but may not account for unique elements of a home or business.
  • To ensure the right size, consult with an HVAC professional.

Need Help?

T&K Airpower has been working to keep homes and businesses comfortable and efficient for over 25 years. Do you need a new air conditioner for your home? If your business in need of an air con? Give us a call, and we will be more than happy to help.