The most common mistake when buying an AC is the wrong size. An undersized unit runs flat out and never cools enough; an oversized one cycles on and off, uses more power and dries the air poorly. Here's how to get it right.
A rough table by area
- up to 25 m² → 9,000 BTU
- 25–40 m² → 12,000 BTU
- 40–60 m² → 18,000 BTU
- 60–90 m² → 24,000 BTU
- over 90 m² → multiple zones or a multi-split system
What else affects it
Floor area is the start, not the whole story. Step up one level if the room has large south-facing windows, sits under the roof (top floor), is poorly insulated, or often holds several people or heat-producing devices. For shaded, north-facing rooms with good insulation, the smaller unit is enough.
Ceiling height
The tables assume ceilings around 2.6 m. If yours are higher — common in older Polog houses — the air volume is larger, so add about 10–15% to the capacity.
Not sure? We'll calculate it
Instead of guessing, tell us the area, floor and orientation, and we'll calculate the exact requirement and suggest a specific model. Try the calculator on the homepage too, or call 078 433 882.