Duct Velocity Calculator

Calculate the air velocity inside a duct of known size carrying a specified airflow.

CFM
in

Air Velocity

859 ft/min

Duct Area50.3 sq in
Noise Risk0

Air Velocity vs Airflow

सूत्र देखें →

सूत्र

## Duct Air Velocity **V = CFM / A** Where A is the cross-sectional area of the duct in square feet. Convert the diameter from inches to feet before calculating the area. Residential duct velocity should stay below 700-900 ft/min to avoid noise.

हल किया गया उदाहरण

300 CFM through an 8-inch round duct.

  1. 01Area = pi x (8/24) squared = 0.349 sq ft
  2. 02Velocity = 300 / 0.349 = 860 ft/min
  3. 03This is borderline for noise; consider a 10-inch duct.