On this page you can estimate the size of the ducts for the correct functioning of the ventilation system. The tool helps to calculate the cross-sectional area of the ducts according to the values of air exchange and air velocity of the air flow. Please note that the recommended velocity for residential areas is 3-5 m/s (but no more than 10 m/s). The required parameters for the calculation can be seen on the notation below. To get the result, click the "Calculate" button.
How to calculate the cross-sectional air duct area?
Formula cross-sectional air duct area: S (m2) = L / (3600 × V)
- L – indoor air exchange, m3/h;
- V – air velocity, m/s.
Formula for calculating rectangular duct side (at A=B): A (mm) = 1000 × √S
Formula for calculating round duct diameter: D (mm) = 1000 × 2 × √(S / 3.14)
- L – cross-sectional area, m2.
Recommended values of air velocity in the ventilation system, m/s
|Main air ducts||3.5-5.0||3.5-6.0||6.0-11.0|