Aircon
How to Choose an Aircon in Singapore: Sizing Guide
When buying air-conditioning, people focus on brand — but getting the size right for the room matters far more. Too small and it never cools; too big and it wastes energy and cycles poorly. Here’s how to choose well.
Key takeaways
- Match the aircon’s capacity (BTU/horsepower) to the room size.
- Choose the system type (System 2/3/4) for the number of rooms.
- Look at energy efficiency (tick rating) for lower running costs.
- Correct installation matters as much as the unit.
Size by room, not by brand
Cooling capacity is measured in BTU (or “horsepower”), and it should match the room. As a rough guide, larger and sunnier rooms, or those with more people and heat-generating appliances, need more capacity.
| Room | Rough capacity guide |
|---|---|
| Small bedroom | ~9,000 BTU (≈1 HP) |
| Master bedroom | ~12,000 BTU (≈1.5 HP) |
| Living / larger room | ~18,000–24,000 BTU (≈2–2.5 HP) |
A guide only — an on-site assessment accounts for sun, layout and usage.
System type and efficiency
Choose a System 2, 3 or 4 based on how many rooms you’re cooling from one condenser — see installation costs. Then compare energy efficiency (the tick rating) — a more efficient unit costs a little more upfront but less to run over the years, which adds up in our climate.
Installation makes or breaks it
Even the best unit underperforms if poorly installed — piping, vacuuming and mounting all matter. Pair the right unit with proper installation and servicing for reliable cooling.
Frequently asked questions
What size aircon do I need? Match BTU/horsepower to the room — bigger, sunnier rooms need more capacity.
Is a bigger aircon always better? No — oversizing wastes energy and cools unevenly; right-sizing is key.
Which system should I get? System 2/3/4 depending on how many rooms you’re cooling.
Does efficiency rating matter? Yes — a higher tick rating means lower running costs over time.
Choosing a new system?
We advise on sizing and handle installation and servicing. See our aircon service and the installation cost guide. Get a free quote today.
