Pressure Drop in Square Duct Calculator

Formula Used:

\[ \Delta P_s = \frac{0.6 \times f \times L \times V_m^2}{\frac{S^2}{2 \times (S + S)}} \]

Friction Factor in Duct (f):

Length of Duct (L):

Mean Velocity of Air (V_m):

m/s

Side (S):

Pressure Drop in Square Duct (ΔP_s):

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1. What is Pressure Drop in Square Duct?

Pressure Drop in Square Duct due to friction is the decrease in the value of the pressure due to the influence of friction in square duct systems. It's an important parameter in HVAC and fluid dynamics calculations.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ \Delta P_s = \frac{0.6 \times f \times L \times V_m^2}{\frac{S^2}{2 \times (S + S)}} \]

Where:

\( \Delta P_s \) — Pressure Drop in Square Duct (Pa)
\( f \) — Friction Factor in Duct (dimensionless)
\( L \) — Length of Duct (m)
\( V_m \) — Mean Velocity of Air (m/s)
\( S \) — Side length of square duct (m)

Explanation: The formula calculates pressure loss due to friction in square ducts, considering the duct geometry and flow characteristics.

3. Importance of Pressure Drop Calculation

Details: Accurate pressure drop calculation is crucial for proper HVAC system design, fan selection, energy efficiency optimization, and ensuring adequate airflow in ventilation systems.

4. Using the Calculator

Tips: Enter friction factor (typically 0.02-0.04 for smooth ducts), duct length in meters, mean air velocity in m/s, and side length in meters. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical friction factor value for ducts?
A: For smooth metal ducts, friction factors typically range from 0.02 to 0.04, depending on surface roughness and Reynolds number.

Q2: How does duct shape affect pressure drop?
A: Square ducts generally have higher pressure drops compared to circular ducts of equivalent cross-sectional area due to different flow characteristics.

Q3: What is the significance of the 0.6 factor?
A: The 0.6 factor accounts for specific flow characteristics and empirical corrections for square duct geometry.

Q4: When is this calculation most important?
A: This calculation is critical in HVAC system design, industrial ventilation, and any application where air is moved through square ductwork.

Q5: How does velocity affect pressure drop?
A: Pressure drop increases with the square of velocity, meaning doubling the velocity quadruples the pressure drop.