1. What is CFM to FPM Conversion?

The CFM to FPM conversion calculates air velocity (feet per minute) from air flow rate (cubic feet per minute) and duct cross-sectional area. This is essential for HVAC system design and air flow analysis.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( FPM \) — Feet per minute (air velocity)
• \( CFM \) — Cubic feet per minute (air flow rate)
• \( Duct\ Area \) — Cross-sectional area of duct in square feet

Explanation: This formula converts volumetric flow rate to linear velocity by dividing the flow rate by the cross-sectional area through which the air is moving.

3. Importance of FPM Calculation

Details: Accurate FPM calculation is crucial for proper HVAC system design, ensuring adequate air distribution, maintaining comfort levels, and optimizing energy efficiency in ventilation systems.

4. Using the Calculator

Tips: Enter CFM value in cubic feet per minute and duct area in square feet. Both values must be positive numbers greater than zero for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between CFM and FPM?
A: CFM measures volumetric air flow (how much air), while FPM measures linear air velocity (how fast air is moving).

Q2: What are typical FPM values in HVAC systems?
A: Typical values range from 500-2000 FPM for supply ducts and 600-900 FPM for return ducts, depending on the application.

Q3: How do I calculate duct area?
A: For rectangular ducts: Area = Width × Height (in feet). For round ducts: Area = π × (Diameter/2)² (convert diameter to feet first).

Q4: Why is FPM important in duct design?
A: Proper FPM ensures adequate air movement, prevents noise issues, maintains system efficiency, and ensures proper air distribution throughout the space.

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