Recommended Air Velocity Values in HVAC Duct Design
Air velocity is one of the most important parameters in HVAC duct design. Selecting the correct air velocity ensures efficient airflow, low noise levels, reduced pressure loss, and proper system performance.
In this guide, we explain recommended air velocity values in HVAC ducts with a practical table used by HVAC engineers and designers.
Why Air Velocity Matters in HVAC Systems
Air velocity directly affects:
- Noise generation inside ducts
- Pressure drop and fan power
- Duct size and installation cost
- Indoor comfort and air distribution
Very high velocity causes noise and energy loss, while very low velocity results in oversized ducts and poor air distribution.
Recommended Air Velocity Values (HVAC)
| Duct Application | Recommended Velocity (FPM) |
|---|---|
| Main Supply Duct | 800 – 1200 |
| Branch Duct | 600 – 900 |
| Return Air Duct | 500 – 800 |
| Fresh Air Intake | 400 – 700 |
| Exhaust Duct | 800 – 1500 |
These values are commonly used for commercial and residential HVAC systems. Final selection depends on project requirements and design standards.
How to Calculate Air Velocity
Air velocity is calculated using the standard HVAC formula:
Air Velocity (FPM) = Airflow (CFM) ÷ Duct Area (ft²)
You can calculate air velocity instantly using our online tool:
👉 Air Velocity Calculator (HVAC)
Related HVAC Calculators
Important Design Notes
- Lower velocities are preferred in noise-sensitive areas
- Higher velocities may be used in limited space conditions
- Always check pressure loss and fan selection
- Follow ASHRAE and local HVAC standards
Proper air velocity selection improves system efficiency and long-term performance.
Disclaimer: This information is provided for HVAC design guidance only. Final system design and approvals remain the responsibility of the project engineer.
