The process of choosing the right residential air conditioner for you can be complicated, particularly when it comes down to size and placement.


This guide will help you make the best decisions for your home.

It is important to choose the correct size residential air conditioner in Brisbane to fit your space. This will ensure that you get maximum cooling and energy savings. A large cooling capacity Brisbane air conditioning service will use more energy. However, smaller units might not cool the room well, leaving you uncomfortable and hot.


Which Size Air Conditioner Do I Need?


The most important thing is the wattage, regardless of whether you are looking for an inverter split system, portable, or reverse-cycle AC.

You’ll generally need 0.15 kilowatts for every square metre. A 20 x 60 m room, for example, would necessitate a residential air conditioner in Brisbane capable of delivering around 3kW.A room measuring around 60 x 60 m would need an air conditioner capable of delivering 9 kW. The air conditioner will not be able to lower the temperature if the room’s wattage is too low.


Select the Air-Conditioning System That Is Appropriate for the Size of Your Room.



Small Room

Medium Room

Large Room

Room Size – Square Metres (m2)

10 – 2- Square Metres

20 – 40 Square Metres

40 – 60 Square Metres

Minimum kilowatts Required

2.8 KW

4.2 KW

5.6 KW

Ideal Air Conditioner Type

Split System,

Window Box, Split System

Split System


What Size Area Do You Need to Cool Down?


The space that you want to heat or cool is the most important piece of information.

The floor area can be calculated by multiplying the room’s length by its width. Ceiling height can be an issue if you have high ceilings, but floor space is the main consideration.

IACS stocks units from 2.6 kW window conditioners to 14 kW reverse cycle split systems.

You will need to have a minimum of 1–1.5 kilowatts of cooling capacity for every 10 square metres of floor area. 

This minimum cooling capacity is sufficient if your home has good insulation. However, homes located in warmer regions of Australia or homes with less insulation will require a stronger residential air conditioner in Brisbane to provide efficient cooling.


Other Influences


It is not enough to measure the area, even though that is a good place to start. The following factors will impact which air conditioner you need:

  • Direction windows facing
  • The size of the windows and glass doors
  • External shade, such as trees and eaves, can be provided by buildings or other structures.
  • Insulate your ceiling and walls.
  • ceiling height 

The flooring in your home could affect the heating performance of your reverse cycle air conditioner during the winter. A room with timber or tile floors will be cooler, while carpeting is an excellent insulator that will keep your home warm and cozy.


Split System Air Conditioner


Split system air conditioners provide the best cooling capabilities and most convenient features for your home. Split systems, which are usually reverse cycled, offer more power than portable and window box systems. However, they take up extra space and must be professionally installed in your home by a licensed technician.

Split systems can also provide air purification and allergen filtration. Split systems are a great choice for heating or cooling multiple rooms simultaneously or large areas such as living or dining rooms.


Small Rooms


We recommend small-capacity air conditioners that have cooling capacities of between 2 kW and 3.5 kW for rooms smaller than 20m2.


Medium Rooms


We recommend medium-capacity air conditioners that have cooling capacities of between 4kW and 6kW for rooms between 20 and 40 square metres.


Large Rooms


We recommend large-capacity air conditioners that have cooling capacities of between 5kW and 9kW for rooms larger than 40 square metres.




Insulation can be a great way to increase the efficiency of your home’s air conditioner. It creates a semi-sealed environment that maintains a constant temperature. You may be able to cool an insulated space with a smaller, more powerful air conditioner than an uninsulated one.

Some homes in Australia use either ceiling insulation or wall insulation. Others are fortunate enough to have both.

Insulation is an important factor in determining the size of the Brisbane air conditioner service that you need. An air conditioner that has the minimum recommended kW can cool insulated rooms. However, this will depend on where you live, the orientation of your windows, and many other factors.




Windows are the other main source of heat or cold in a room. Direct sunlight can cause a room to experience higher internal temperatures. The chill will also be able to pass through the window, particularly on cold mornings.




It is important to consider the elevation and position of your house. Australia is well-known for its diversity of climates. It has everything, from the warmest rural areas to the coldest mountain regions. You need an air conditioner that can comfortably manage your environment.

For homes in colder or warmer areas, you might need a model that is more powerful than the room’s capacity to combat external temperature fluctuations.


Talk to Professional Air Conditioning Contractors in Brisbane


An investment in residential air conditioning in Brisbane can be a long-lasting one. It is crucial to choose the right size air conditioner for your house to achieve maximum performance and efficiency. It is better to seek out professional air conditioning contractors in Brisbane, like us at IACS, with years of experience, rather than rush to decide based only on the recommendations of others (yes, even your neighbours).  Contact IACS today for advice.