1. What Is Round Duct Velocity?

Round duct velocity refers to the speed at which air or fluid moves through a circular duct. It is a critical parameter in HVAC systems, ventilation design, and fluid dynamics applications where proper airflow management is essential.

2. How Does The Calculator Work?

The calculator uses the velocity formula:

Where:

• \( V \) — Velocity (m/s)
• \( Q \) — Flow rate (m³/s)
• \( r \) — Radius of the duct (m)
• \( \pi \) — Mathematical constant (approximately 3.1416)

Explanation: The formula calculates velocity by dividing the volumetric flow rate by the cross-sectional area of the circular duct.

3. Importance Of Velocity Calculation

Details: Proper velocity calculation is essential for designing efficient ventilation systems, ensuring adequate airflow, minimizing pressure drops, and optimizing energy consumption in HVAC applications.

4. Using The Calculator

Tips: Enter flow rate in cubic meters per second (m³/s) and radius in meters (m). Both values must be positive numbers greater than zero.

5. Frequently Asked Questions (FAQ)

Q1: Why is duct velocity important in HVAC systems?
A: Proper duct velocity ensures efficient airflow, reduces noise levels, prevents pressure losses, and maintains system performance and energy efficiency.

Q2: What are typical velocity ranges for HVAC ducts?
A: For main ducts: 6-12 m/s, branch ducts: 4-8 m/s, and final runs: 1.5-4 m/s, though specific requirements may vary based on application.

Q3: How does duct size affect velocity?
A: Larger ducts with the same flow rate will have lower velocities, while smaller ducts will have higher velocities for the same flow rate.

Q4: Can this calculator be used for liquids as well as air?
A: Yes, the formula applies to any fluid flowing through a circular duct, though the physical properties of the fluid may affect other system parameters.

Q5: What if I have diameter instead of radius?
A: Simply divide the diameter by 2 to get the radius, or use the formula V = 4Q/(π × d²) where d is the diameter.