Duct Sizing Rechner — Formel
## HVAC Duct Sizing
Duct size is determined by the airflow requirement and an acceptable air velocity.
### Formula
**A = Q / V** (required area)
**D = sqrt(4Q / (pi V))** (circular duct diameter)
where Q is airflow in m^3/s and V is maximum velocity in m/s. Higher velocity means smaller ducts but more noise and pressure drop.
Duct size is determined by the airflow requirement and an acceptable air velocity.
### Formula
**A = Q / V** (required area)
**D = sqrt(4Q / (pi V))** (circular duct diameter)
where Q is airflow in m^3/s and V is maximum velocity in m/s. Higher velocity means smaller ducts but more noise and pressure drop.
Lösungsbeispiel
300 L/s airflow with 6 m/s maximum velocity.
- Q = 300 L/s = 0.30 m^3/s
- A = 0.30 / 6 = 0.05 m^2 = 50,000 mm^2
- D = sqrt(4 x 0.30 / (pi x 6)) x 1000 = sqrt(0.0637) x 1000 = 252 mm
- Round up to next standard size: 250 or 300 mm duct.