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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.

September 28, 2023
Mitch, the technician that came out to inspect our unit was excellent. He arrived promptly and conducted a thorough service. The unit on the property was about 15 years old but he found major faults that required it to be immediately shut down at the mains. Drainage tubes propped up on cardboard boxes, sagging in the middle. The fan axle wrapped in electrical wires, and rubber mounts that had delaminated due to friction and heat. He provided photos of everything, and a quotations for repair and replacement. Frankly, Mitch might have stopped the house burning down, and for that, he and T&K get a five star review.
samantha watson
samantha watson
September 14, 2023
The T&K crew are amazing. Special shout out to Nicole for being so friendly helpful, understanding, and a straight up communication Queen. Steve is professional and helpful. We had a few tradies through, because the job wasn't straight forward, they were all friendly, helpful, super polite, and didn't leave rubbish everywhere. 10/10 would recommend.
Evan Hunt
Evan Hunt
September 13, 2023
We have been using TK Airpower now for a number of years to service or repair our reverse cycle aircon. Living out of town you rely on punctuality and professional work. On every occasion our expectations have been more than met. The company offers an annual maintenance service and performance check which in our case has been done by Nathan who has advised of any problems and carried out any necessary repairs in an efficient and cordial manner. We find the service charge when compared to other electrical service companies highly favourable and payable by card on the day. Our trust in the company has been extended to having no hesitation in leaving the service team alone to finish the job when we had to attend to an unscheduled appointment.
Scott “ScottG” Gully
Scott “ScottG” Gully
September 12, 2023
Absolutely fantastic service. I was referred to this business by Mitsubishi as they are an authorised dealer for the brand as I had issues with my WiFi connection. Steve was so accommodating. To the point of after I had contacted them for help he followed up with a phone call and an email with information on how to go about reconnecting the WiFi side of my system. This level of service in this day and age is very rare . I highly recommend this company and will continue to use it in the future for all of my aircon needs. Regards Scott G
Mark Halliday
Mark Halliday
June 14, 2023
Excellent company. Prompt, friendly service.
mike yardley
mike yardley
May 19, 2023
This is the second time we have used TK Air power We find they are professional trustworthy informative and reliable with friendly techs Adam did our job this time and it was a pleasure to have him in our home Thanks Adam and thanks TK Air power Mike Yardley Greenwith
Adam Beecken
Adam Beecken
May 18, 2023
We recently spoke with T&K AirPower about supply and fitting of a new ducted reverse cycle air conditioner for our home, we’ve always had evaporative ducted air-conditioning but never refrigerated. They gave us a few options but we went for the Mitsubishi Electric knowing they’re one of the best on the market, they also advised us adding the Air Touch 5 controller so we can control via an app and also turn on our system prior to getting home. Installation went smoothly, the guys were on time, friendly and communicated well, they showed us how to use the system and cleaned up before leaving. We will definitely tell our friends and refer T&K AirPower to others, Thx Adam and Cindy
Steve Brown
Steve Brown
May 17, 2023
Excellent customer service. Dealt professionally with my insurance company. I would highly recommend. Nicole was a pleasure to deal with!
Grant Cooper
Grant Cooper
April 28, 2023
Very prompt service. Cost less than was quoted originally because the job turned out to be not so difficult.