Mini Split Size Calculator
Here’s a comprehensive table to help you determine the appropriate mini-split (ductless AC) size for a garage, considering factors such as garage size, insulation level, climate, and BTU requirements.
Mini Split Size Guide for Garage
| Garage Size (Sq Ft) | Insulation Level | Climate Zone | Recommended BTU (Cooling) | Recommended BTU (Heating) | Mini Split Unit Size (Tons) | Notes |
|---|---|---|---|---|---|---|
| 200-300 sq ft | Well-Insulated | Mild | 6,000 - 9,000 BTU | 6,000 - 9,000 BTU | 0.5 - 0.75 Ton | Ideal for single-car garages with good insulation in mild climates. |
| Poorly Insulated | Hot | 9,000 - 12,000 BTU | 10,000 - 12,000 BTU | 0.75 - 1 Ton | For warmer climates, increase BTU to compensate for poor insulation. | |
| 400-500 sq ft | Well-Insulated | Mild | 12,000 - 15,000 BTU | 12,000 - 15,000 BTU | 1 - 1.25 Ton | Typical for two-car garages; mild climates and good insulation require less BTU. |
| Poorly Insulated | Hot/Cold | 15,000 - 18,000 BTU | 18,000 - 20,000 BTU | 1.25 - 1.5 Ton | Increase BTU in regions with extreme temperatures or poor insulation. | |
| 600-700 sq ft | Well-Insulated | Mild | 18,000 - 20,000 BTU | 18,000 - 20,000 BTU | 1.5 - 2 Ton | Suitable for large or converted garages; insulation can reduce BTU needs. |
| Poorly Insulated | Hot/Cold | 20,000 - 24,000 BTU | 24,000 - 26,000 BTU | 2 Ton | Extreme temperatures and lack of insulation require higher BTU. | |
| 800-1,000 sq ft | Well-Insulated | Mild | 24,000 - 28,000 BTU | 24,000 - 28,000 BTU | 2 - 2.5 Ton | Large garage or shop space; good insulation allows for lower BTU in mild areas. |
| Poorly Insulated | Hot/Cold | 28,000 - 36,000 BTU | 30,000 - 36,000 BTU | 2.5 - 3 Ton | High BTU is essential for large, uninsulated spaces in extreme climates. |
Key Considerations
- Insulation Level: Well-insulated garages retain temperatures better, requiring fewer BTUs to maintain comfort. Poor insulation means the unit has to work harder, especially in extreme climates.
- Climate Zone:
- Mild: Average summer temperatures below 30°C (86°F) and winter temperatures above 0°C (32°F).
- Hot: Summer temperatures regularly above 30°C (86°F).
- Cold: Winter temperatures regularly below 0°C (32°F).
- Unit Size (Tons): Typically, 1 ton equals 12,000 BTU. For very hot or cold regions, opt for a unit on the higher end of the BTU range.
- Ventilation & Air Circulation: If the garage is used as a workspace, proper ventilation is essential. Consider adding a ceiling fan to improve air circulation and efficiency of the mini-split.
- Usage: If the garage is primarily for vehicle storage, a lower BTU rating may be sufficient. For workshops or other uses, choose a higher BTU to maintain comfort.
- Temperature Control: For garages located in regions with large temperature fluctuations, select a mini-split with both heating and cooling capabilities (typically available with inverter technology).