1. What is FPM to CFM Conversion?

The FPM to CFM conversion calculates airflow volume from velocity measurements. CFM (Cubic Feet per Minute) measures the volume of air flow, while FPM (Feet per Minute) measures the speed of air movement.

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• \( CFM \) — Cubic Feet per Minute (volume flow rate)
• \( FPM \) — Feet per Minute (velocity)
• \( A \) — Area in square feet (cross-sectional area)

Explanation: This formula converts velocity measurement (FPM) to volume flow rate (CFM) by multiplying by the cross-sectional area through which the air is flowing.

3. Importance of CFM Calculation

Details: CFM calculations are essential for HVAC system design, ventilation requirements, industrial exhaust systems, and airflow analysis 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 will provide the airflow rate in cubic feet per minute.

5. Frequently Asked Questions (FAQ)

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

Q2: Where is this conversion commonly used?
A: HVAC system design, ductwork calculations, industrial ventilation, fan selection, and airflow measurement in various industries.

Q3: How do I measure the area for the calculation?
A: Measure the cross-sectional area of the duct, pipe, or opening through which air is flowing. For rectangular ducts: width × height. For circular ducts: π × (radius)².

Q4: Can I use this for liquid flow calculations?
A: While the principle is similar, liquid flow typically uses different units (GPM instead of CFM) and may require additional factors for viscosity and density.

Q5: What are typical FPM values in HVAC systems?
A: Typically 600-900 FPM for supply ducts, 500-700 FPM for return ducts, and 300-500 FPM for branch ducts in residential systems.