1. What is Air Pressure Loss in Pipes?

Definition: This calculator estimates the pressure drop (loss) of air flowing through a pipe due to friction and other factors.

Purpose: It helps HVAC engineers, pneumatic system designers, and industrial process engineers determine pressure requirements for air systems.

2. How Does the Calculator Work?

The calculator uses the Darcy-Weisbach equation:

Where:

• \( \Delta P \) — Pressure loss (Pascals)
• \( f \) — Darcy friction factor (dimensionless)
• \( L \) — Pipe length (meters)
• \( \rho \) — Air density (kg/m³)
• \( v \) — Air velocity (m/s)
• \( D \) — Pipe diameter (meters)

Explanation: The formula calculates the pressure drop caused by friction between the moving air and the pipe walls.

3. Importance of Pressure Loss Calculation

Details: Accurate pressure loss estimation ensures proper system design, adequate fan/pump sizing, and energy-efficient operation of air systems.

4. Using the Calculator

Tips: Enter the friction factor (default 0.02 for smooth pipes), pipe length, air density (default 1.225 kg/m³ at sea level), air velocity, and pipe diameter. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: How do I determine the friction factor?
A: For laminar flow (Re < 2300), f = 64/Re. For turbulent flow, use Moody chart or Colebrook equation based on pipe roughness.

Q2: What's typical air density?
A: At sea level and 15°C, it's 1.225 kg/m³. Adjust for altitude or temperature (lower at higher altitudes/temperatures).

Q3: What's a reasonable air velocity?
A: Typically 5-20 m/s for compressed air systems, lower for HVAC ducts (2-5 m/s) to reduce noise and pressure loss.

Q4: Does this include fittings losses?
A: No, this is only for straight pipe. Add equivalent lengths or K-factor methods for fittings.

Q5: How do I convert the result to other units?
A: 1 Pa = 0.000145 psi = 0.004014 inH₂O = 0.00001 bar.