How to Choose the Right Size Air Conditioner for Your Space
Get the right AC system for your home or office in Canberra
Choosing the correct size air conditioner is one of the most important decisions when it comes to comfort, energy efficiency, and long-term performance. If your system is too small, it will struggle to keep up with demand. Too big, and you’ll waste energy and money.
Here’s how to work out what size air conditioner you need—and why it matters.
Step 1: Measure Your Space
First, calculate the size of the room or area you want to cool or heat. Use square metres (m²) as your measurement and include any open areas like hallways or adjacent rooms that can’t be sealed off. This will help you determine the cooling capacity (in kilowatts or kW) you’ll need.
Step 2: Use a Basic Guide
Once you have your room size, refer to this general guide to match your space to the right AC size:
Step 3: Consider Other Factors
Room size is only part of the equation. In Canberra, we experience extreme seasonal changes, so it's also important to factor in:
- Window size and orientation – Large north-facing windows can increase heat load.
- Ceiling height – Higher ceilings mean more air to condition.
- Insulation – Well-insulated spaces retain temperature better.
- Room use – Kitchens and high-traffic areas often require larger units.
Need Help Deciding?
If you're unsure which system is right for your home or business, AGA Air Conditioning is here to help. We offer free quotes across Canberra and can recommend the best split system, ducted, or multi-head solution based on your space, usage, and budget.
