Table Of Contents

With the Aussie sun cranking up the heat, your place may start to feel like a scene from a desert adventure. Fear not – we're here to chat about a hero in the world of home comfort: the split system air conditioner. Picture this: scorching heat outside, but you're living the cool life inside. Now, to get that perfect oasis at home, you've got to answer the million-dollar question – what size air conditioner do you need?

Stick around, mate. We're about to turn the heat down and find you the ideal cooling sidekick for your Aussie haven. Let's dive into the nitty-gritty and make your place the ultimate chill zone. Ready to ride the breeze with us and find the right-sized air conditioning system for your home? Let's dive in!

Understanding Cooling Capacity

The total cooling capacity of an air conditioner is typically measured in kilowatts (kW) and determines how much overall heat the unit can remove from a room per hour. Choosing the right capacity ensures your air conditioner is effective and efficient in maintaining a comfortable temperature.

Factors Influencing the Sizing of Split System ACs

Room size

The size of the room is a primary determinant in choosing the right split-system air conditioner. For accurate sizing, measure the length and width of the room and multiply the two dimensions to get the total area in square metres.

Small rooms (up to 20 square metres) generally need 2.5kW units, medium-sized rooms (20-40 square metres) require around 3.5kW, while larger rooms (40-60 square metres) might need 5-6kW units.


The insulation factor is often overlooked but is crucial for maintaining a consistent temperature. Consider the quality of insulation in your walls, ceiling, and floors. Well-insulated homes require less cooling capacity since they retain cool air more effectively. Conversely, poorly insulated homes may need air conditioners with higher capacity to compensate for heat exchange with the external environment.

Ceiling height

Ceiling height impacts the air circulation within a room. For spaces with higher ceilings, you'll need a unit with a greater cooling capacity to ensure even cool air distribution. As a general guideline, for every additional metre of ceiling height beyond the standard 2.4 metres, consider adding 10% to the recommended cooling capacity.

Windows and sunlight exposure

The number and size of windows, along with their orientation, significantly affect the heat load in a room. South-facing windows receive less direct sunlight, while north-facing windows may be exposed to the sun for extended periods. Consider installing window coverings to minimise heat gain. Adjust the cooling capacity calculation by factoring in the amount of sunlight your room receives during peak hours.

Climate zone

Australia's diverse climate zones range from tropical in the north to temperate in the south. Understanding your local climate is vital for selecting the appropriate cooling capacity. Hotter regions like Queensland may necessitate higher capacity units to tackle extreme temperatures effectively.

Crunch the Numbers: Calculate Your Cool Quotient

Let's embark on a numerical journey to unveil the secret sauce of optimal cooling capacity. It's like solving a puzzle where each piece contributes to the perfect chill. So, grab your calculators and break down the process of calculating your cool quotient step by step.

Measure twice, cool once

First, grab the tape measure and get the dimensions of your room. Length multiplied by width gives you the total area in square metres. This magic number becomes the foundation of your cooling capacity calculation. Small rooms, big rooms, and everything in between – each has its own cooling demands.

Height matters: Consider ceiling height

Now, let's look up – quite literally. Ceiling height plays a role in the air circulation game. For every additional metre of height beyond the standard 2.4 metres, add 10% to the recommended cooling capacity. High ceilings need a bit more oomph to ensure the cool air reaches every nook and cranny.

Insulation factor

Insulation isn't just about warmth in winter; it's also your secret weapon for coolness. Assess your home's insulation – the walls, ceiling, and floors. Well-insulated homes may need less cooling capacity, while poorly insulated ones require a bit more muscle. Apply an insulation factor to your calculation to fine-tune the numbers.

Sunlight factor

Windows are the portals to natural light but also usher in heat—factor in the number and size of windows, along with their direction. South-facing windows get less direct sunlight while north-facing ones soak up the rays. Adjust your calculation to account for the sun's influence on your room's temperature.

Climate wisdom: Considering your region

Australia's vastness brings diverse climates, from the scorching north to the temperate south. Know your climate zone – hotter regions may require beefier cooling capacities to combat soaring temperatures. Consider this regional wisdom in your calculation for a tailored approach.

What Not to Do When Selecting Your AC Size


Consider undersizing as the cardinal sin of air conditioning. It's akin to bringing a squirt gun to a firefight. When your air conditioner cannot match your room size, it's forced into an uphill battle, running tirelessly to cool a space it was never designed for. The result? Skyrocketing energy bills, compromised efficiency, and a living space that's more lukewarm than cool.

To avoid this blunder, carefully calculate the cooling capacity your room demands. Factors like room size, insulation, and even the local climate should be considered. Think big enough to handle the heat but not so big that you're paying for power you don't need.


Conversely, the allure of bigger, more powerful units can lead to oversizing – another misstep to dodge. Choosing an air conditioner with excessive capacity might sound like a grand idea, but it often leads to a series of quick on-and-off cycles. This not only wears out your system faster but also hampers overall efficiency.

It's like having a Formula 1 car for your daily commute – impressive but impractical. Aim for a sweet spot that matches your room's needs when sizing up your unit without going overboard. Efficiency and longevity will be your rewards for this well-balanced approach.

Neglecting insulation

Insulation, the unsung hero of the cool comfort saga, often goes unnoticed until it's too late. Picture this: you've got the perfect air conditioner, but without proper insulation, the cool air you're paying for is slipping away through gaps in your home's armour.

Before diving into the specifics of your air conditioning unit, take a moment to assess your insulation game. Windows, doors, and even the roof – ensure they all contribute to the cause. After all, insulation isn't just about keeping the heat out; it's about keeping your cool where it belongs.

Energy Efficiency Considerations

  • Energy Star Ratings: Consider split system air conditioners with high Energy Star ratings. The more stars, the more energy-efficient the unit is. This benefits the environment and translates to cost savings on your electricity bills in the long run.
  • Inverter Technology: Consider units with inverter technology, which adjusts the compressor speed according to the space's cooling needs. This leads to more stable and energy-efficient operation compared to traditional non-inverter models.
  • Smart Features: Some modern split system air conditioners have smart features like programmable thermostats and remote access. These features allow you to optimise energy usage by scheduling cooling periods according to your daily routine and remotely controlling the system when needed.

Navigating Your Cooling Needs with Expert Help

Alright, you've dived deep into the world of split system air conditioners, and now you're armed with the knowledge to keep your home cool. Remember, it's not just about getting any old unit; it's about finding the Goldilocks of air conditioners – not too big, not too small, just right. Calculating cooling capacity is a bit like a science experiment for your home.

Measure your room, consider future changes, and factor in the number of humans and gadgets cooking up a storm. And hey, if you're feeling adventurous, go for those smart features – because who doesn't love a bit of tech-savvy comfort?

However, here's the clincher: don't go it alone. Even superheroes need a sidekick. Consider seeking expert help for installation and fine-tuning. These folks know their ducts from their vents, ensuring your cooling setup is as smooth as a summer breeze.

So, there you have a roadmap to finding the perfect split system for your Aussie abode. Stay cool, stay comfortable, and when in doubt, call the experts to turn up the chill factor in your home. Cheers to cool comfort!

Get A Free Air Con Quote

Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.
More from Our Blog

You Might Also Like

See All Posts