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Air Duct Equation:
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The Air Duct Calculator determines the required airflow (CFM) for proper ventilation system design. It calculates cubic feet per minute based on room volume and desired air changes per hour, essential for HVAC duct sizing and system planning.
The calculator uses the air duct equation:
Where:
Explanation: The equation converts air changes per hour to cubic feet per minute by dividing by 60 minutes, providing the airflow rate needed for proper ventilation.
Details: Accurate CFM calculation is crucial for designing efficient HVAC systems, ensuring proper air circulation, maintaining indoor air quality, and meeting building code requirements for ventilation.
Tips: Enter room volume in cubic feet and desired air changes per hour. Typical ACH values range from 4-8 for residential spaces, 6-12 for commercial spaces, and higher for specialized environments like laboratories or kitchens.
Q1: What is CFM and why is it important?
A: CFM (Cubic Feet per Minute) measures airflow volume. It's essential for proper HVAC system sizing to ensure adequate ventilation and comfort.
Q2: How do I calculate room volume?
A: Multiply room length × width × height in feet. For irregular rooms, calculate volume of each section separately and sum them.
Q3: What are typical ACH values for different rooms?
A: Living rooms: 4-6 ACH, bedrooms: 4-5 ACH, kitchens: 8-15 ACH, bathrooms: 8-10 ACH, offices: 6-8 ACH.
Q4: Can this calculator be used for commercial buildings?
A: Yes, but commercial spaces often have specific code requirements and may need professional HVAC design for complex systems.
Q5: How does CFM relate to duct size?
A: Higher CFM requires larger duct sizes. Duct sizing also depends on air velocity, with typical residential systems using 600-900 FPM velocity.