1. What is Square Duct CFM Calculation?

CFM (Cubic Feet per Minute) is a measurement of airflow volume. For square ducts, CFM is calculated by multiplying the air velocity by the cross-sectional area of the duct.

2. How Does the Calculator Work?

The calculator uses the CFM formula:

Where:

• \( Velocity \) — Air velocity in feet per minute (ft/min)
• \( Area \) — Cross-sectional area in square feet (sq ft)

Explanation: This calculation determines the volume of air moving through a square duct per minute, which is essential for proper HVAC system design and analysis.

3. Importance of CFM Calculation

Details: Accurate CFM calculation is crucial for proper HVAC system design, ensuring adequate ventilation, maintaining indoor air quality, and optimizing energy efficiency in buildings.

4. Using the Calculator

Tips: Enter velocity in ft/min and area in sq ft. Both values must be positive numbers. For square ducts, area is calculated as side × side.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical velocity range for HVAC ducts?
A: Typical velocities range from 600-900 ft/min for supply ducts and 500-700 ft/min for return ducts in commercial systems.

Q2: How do I calculate area for a square duct?
A: For a square duct, area = side length × side length (in square feet).

Q3: Why is CFM important in HVAC systems?
A: CFM determines how much air is being delivered to a space, affecting temperature control, ventilation rates, and overall comfort.

Q4: Can this calculator be used for rectangular ducts?
A: Yes, as long as you calculate the correct cross-sectional area (width × height).

Q5: What factors affect air velocity in ducts?
A: Fan power, duct size, duct material, number of bends, and filters all affect air velocity in duct systems.