1. What is a Pipe Air Flow Rate Calculator?

Definition: This calculator estimates the volumetric flow rate of air through a pipe in gallons per minute (GPM) equivalent.

Purpose: It helps HVAC engineers, pneumatic system designers, and technicians determine air flow rates for system design and analysis.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Q \) — Flow rate (GPM equivalent)
• \( V \) — Air velocity (ft/s)
• \( A \) — Cross-sectional area of pipe (ft²)
• 448.83 — Conversion factor (ft³/s to GPM)

Explanation: The formula converts the volumetric flow rate from cubic feet per second to gallons per minute equivalent.

3. Importance of Air Flow Rate Calculation

Details: Proper air flow estimation ensures efficient system operation, proper ventilation, and correct component sizing in pneumatic systems.

4. Using the Calculator

Tips: Enter the air velocity in feet per second and the pipe's cross-sectional area in square feet. Both values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why convert to GPM when measuring air flow?
A: GPM equivalent provides a familiar unit for comparison with liquid flow rates in integrated systems.

Q2: What's a typical air velocity in pipes?
A: For HVAC systems, typical velocities range from 10-25 ft/s in ducts, while compressed air systems may use 20-40 ft/s.

Q3: How do I calculate pipe area?
A: For circular pipes: \( A = \pi \times (D/2)^2 \) where D is diameter in feet.

Q4: Does this account for pressure changes?
A: No, this is for incompressible flow approximation. For high-pressure systems, use more detailed compressible flow equations.

Q5: What's the 448.83 conversion factor?
A: It converts cubic feet per second to gallons per minute (1 ft³/s = 448.83 GPM).