Sizing your Aircon
Choosing the Right Air Conditioner Size for Your Space
Selecting the correct air conditioner size is key to ensuring comfort, efficiency, and long-term performance. At Swift Air, we’ve created an easy-to-follow sizing guide based on the standard 600 BTU per square meter rule — ideal for Johannesburg’s climate.
However, it’s important to note that this is just a guideline. Several factors can affect the size you need, including:
- Ceiling height
- Room insulation
- Number of occupants
- Sun exposure (especially in north- or west-facing rooms)
- Heat-generating appliances or equipment
If you're unsure, our team is happy to assess your space and recommend the most suitable unit. Getting the size right from the start means better comfort, lower energy bills, and a longer-lasting system.
To calculate the square meterage of a room, simply multiply the length by the width (in meters). The table below serves as a general guideline for selecting an appropriate air conditioning unit, based on an estimated requirement of 600 BTU per square meter.
| Room Size Range (m²) | Closest Standard Aircon Size |
|---|---|
| 10 – 15 m² | 9,000 BTU |
| 16 – 20 m² | 12,000 BTU |
| 21 – 30 m² | 18,000 BTU |
| 31 – 40 m² | 24,000 BTU |
| 41 – 50 m² | 30,000 BTU |
| 51 – 60 m² | 36,000 BTU |
| 61 – 80 m² | 48,000 BTU |
| 81 – 100 m² | Cassette / Ducted Unit |
| 100+ m² | Site Visit Required |