1. What is FPM to CFM Conversion?

The FPM to CFM conversion calculates airflow volume from velocity and cross-sectional area. CFM (Cubic Feet per Minute) measures volumetric flow rate, while FPM (Feet per Minute) measures linear velocity.

2. How Does the Calculator Work?

The calculator uses the fundamental airflow formula:

Where:

• \( CFM \) — Cubic Feet per Minute (volumetric flow rate)
• \( FPM \) — Feet per Minute (linear velocity)
• \( A \) — Cross-sectional Area (square feet)

Explanation: This formula converts linear air speed (FPM) to volumetric airflow (CFM) by multiplying velocity by the cross-sectional area through which air flows.

3. Importance of CFM Calculation

Details: CFM calculation is essential for HVAC system design, ventilation planning, industrial exhaust systems, and airflow optimization in various engineering applications.

4. Using the Calculator

Tips: Enter velocity in feet per minute and area in square feet. Both values must be positive numbers. The calculator provides accurate CFM results for airflow analysis.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between FPM and CFM?
A: FPM measures how fast air moves (speed), while CFM measures how much air moves (volume per minute).

Q2: When is this conversion most commonly used?
A: Primarily in HVAC design, ductwork sizing, ventilation systems, and industrial airflow applications.

Q3: How do I measure the cross-sectional area?
A: For rectangular ducts: width × height. For circular ducts: π × (radius)². Convert to square feet if needed.

Q4: What are typical FPM values in ventilation systems?
A: Typically 500-2000 FPM for supply ducts, 600-900 FPM for return ducts, depending on application.

Q5: Can this formula be used for liquids as well?
A: Yes, the principle applies to any fluid flow, though units would change (e.g., GPM instead of CFM for water).