Wondering what size air conditioner is right for your Perth home? Choosing the correct AC size isn’t just about comfort, it’s about performance, energy efficiency, and keeping costs under control. An undersized unit will struggle to cool your space, while an oversized one may cycle on and off too frequently, wasting energy and leaving you uncomfortable.
In this guide, we’ll show you how to determine the right air conditioner size for your home based on room size, insulation, layout, and Perth’s climate. Plus, learn why a professional installation from WestOz Trades can help you get it right the first time.
Why Air Conditioner Size Matters
An AC unit that’s too small will run constantly, fail to maintain a stable temperature, and wear out faster. If it’s too large, it may cool the space too quickly without properly removing humidity, leading to uncomfortable conditions and higher power bills.
Choosing the right air conditioner size ensures better energy efficiency, lower running costs, and long-lasting performance.
Key Factors That Affect AC Sizing
Room Size and Layout
Measure the square metres of the space. As a general rule of thumb:
- – 20–30 sqm: 2.5 kW unit
- – 30–45 sqm: 3.5 kW unit
- – 45–60 sqm: 5–6 kW unit
- – 60+ sqm: 7–9 kW unit
Open-plan living, high ceilings, or unusual layouts may require a tailored approach.
Insulation and Building Materials
Well-insulated homes retain cool air better, allowing for smaller AC units. Poor insulation, gaps around windows or doors, and certain materials like brick or concrete can affect how your home retains or absorbs heat.
Window Orientation and Sun Exposure
North or west-facing windows let in more heat. Large windows exposed to sunlight increase the cooling load. Consider window treatments or double glazing for improved thermal efficiency.
Perth Climate Conditions
With hot, dry summers and mild winters, Perth homes need cooling systems that can handle prolonged heat. Choosing the correct size helps your AC perform reliably during peak summer temperatures.
Don’t Guess—Get Expert Help
Online calculators offer general guidance, but they don’t account for unique factors like layout, ceiling height, or airflow. The most accurate way to size your AC is with a professional heat load assessment. WestOz Trades offers expert air conditioning installation in Perth, helping homeowners find a system that fits their space, budget, and comfort needs.
Why Choose WestOz Trades
WestOz Trades Air Conditioning Services specialises in tailored cooling solutions across Perth. We take the guesswork out of AC sizing and offer full-service installation, maintenance, and support. From small apartments to large family homes, we ensure your system is efficient, reliable, and built to last.
Our team will assess your home, recommend the ideal system size, and complete the installation with precision and care.
Final Tip: Size It Right, Stay Comfortable
Choosing the right air conditioner size for your Perth home is essential for comfort and cost savings. Avoid the risks of going too small or too large, get expert advice from WestOz Trades and invest in a system that works as hard as you do.
Contact us today for personalised recommendations and air conditioning solutions that keep your home cool all summer long.
