1. What is FPM to CFM Conversion?

The FPM to CFM conversion calculates the volumetric flow rate (CFM) from velocity (FPM) and cross-sectional area. This is essential in HVAC, ventilation systems, and airflow measurements where understanding air volume movement is critical.

2. How Does the Calculator Work?

The calculator uses the fundamental flow rate formula:

Where:

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

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

3. Importance of CFM Calculation

Details: CFM calculations are vital for proper HVAC system design, ventilation requirements, dust collection systems, and ensuring adequate air exchange rates in buildings and industrial 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 flow rate in cubic feet per minute.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between FPM and CFM?
A: FPM measures velocity (speed of air movement), while CFM measures volumetric flow rate (volume of air moving per minute).

Q2: How do I measure the area for duct calculations?
A: For rectangular ducts: width × height. For circular ducts: π × (radius)² or π × (diameter/2)².

Q3: 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.

Q4: Can I use this for liquid flow calculations?
A: The principle is the same, but units would change (e.g., GPM instead of CFM for gallons per minute).

Q5: Why is CFM important in ventilation?
A: CFM determines how much air is being moved, which is crucial for maintaining air quality, temperature control, and meeting building code requirements.