Fan & Blower Sizing Calculator
Determine the optimal fan size for your ventilation needs with our advanced calculator. Get precise CFM, static pressure, and power requirements.
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Fan Sizing Results
Room Volume:
–
ft³
Required CFM:
–
ft³/min
Static Pressure:
–
in. wg
Estimated Power:
–
Watts
Fan Type Recommendation:
–
Recommended Fans
Enter your parameters to see recommended fan models.
How to Use This Calculator
- Enter your room dimensions in feet (length × width × height)
- Select the desired air changes per hour (ACH) based on room type
- Input your duct system length and diameter
- Select the level of obstructions in your system
- Choose your elevation above sea level
- Click “Calculate” to get your fan requirements
Calculation Formulas
Room Volume: Length × Width × Height
Required CFM: (Room Volume × ACH) ÷ 60
Static Pressure: (Duct Length × 0.03 × Obstruction Factor) ÷ (Duct Diameter ÷ 12)
Power Estimate: (CFM × Static Pressure) ÷ (6356 × Fan Efficiency (assumed 60%))
Expert Tips for Fan Selection
- For bathrooms, aim for 8-10 ACH
- Kitchens require 12-15 ACH for proper ventilation
- Always add 10-15% safety factor to calculated CFM
- Consider noise levels – larger fans at lower speeds are often quieter
- For long duct runs (>20 ft), consider increasing duct diameter