1. What is CFM Calculation?

CFM (Cubic Feet per Minute) calculation converts FPM (Feet per Minute) to CFM using duct area. It's essential for HVAC system design and airflow measurement in ventilation systems.

2. How Does the Calculator Work?

The calculator uses the CFM formula:

Where:

• \( CFM \) — Cubic feet per minute (ft³/min)
• \( FPM \) — Feet per minute (ft/min)
• \( \text{Duct Area} \) — Cross-sectional area of duct (ft²)

Explanation: The equation calculates the volume of air flow by multiplying the velocity (FPM) by the cross-sectional area of the duct.

3. Importance of CFM Calculation

Details: Accurate CFM calculation is crucial for proper HVAC system design, ventilation requirements, and ensuring adequate air circulation in buildings and industrial applications.

4. Using the Calculator

Tips: Enter FPM in feet per minute and duct area in square feet. All values must be valid (FPM > 0, area > 0).

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between CFM and FPM?
A: FPM measures air velocity (speed), while CFM measures air volume flow rate. CFM = FPM × Area.

Q2: How do I measure duct area?
A: For rectangular ducts: width × height. For circular ducts: π × (radius)². Convert measurements to square feet.

Q3: What are typical FPM values in HVAC systems?
A: Typical values range from 600-2000 FPM for supply ducts and 500-1500 FPM for return ducts, depending on the application.

Q4: Why is CFM important in ventilation?
A: CFM determines the amount of air being moved, which is critical for maintaining air quality, temperature control, and meeting building code requirements.

Q5: Can this calculator be used for different duct shapes?
A: Yes, as long as you provide the correct cross-sectional area in square feet for any duct shape.