Ventilation Calculator
Duct sizing by air flow rate
Flow rate Q, l/s
3333.3
Find cross-section area
→
Area, m²
0.3030
F = Q / (3600 × v × k)
Find air velocity
→
Velocity, m/s
4.02
v = Q / (3600 × F × k)
Velocity:< 2 m/s2–4 m/s4–6 m/s6–8 m/s> 8 m/s
Round Ducts
| ∅, mm | 100 | 125 | 160 | 200 | 250 | 280 | 315 | 355 | 400 | 450 | 500 | 560 | 630 | 710 | 800 | 900 | 1000 | 1100 | 1200 | 1300 | 1400 | 1500 | 1600 | 1700 | 1800 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| v, m/s | 424.63 | 271.76 | 165.87 | 106.16 | 67.94 | 54.16 | 42.79 | 33.69 | 26.54 | 20.97 | 16.99 | 13.54 | 10.70 | 8.42 | 6.63 | 5.24 | 4.25 | 3.51 | 2.95 | 2.51 | 2.17 | 1.89 | 1.66 | 1.47 | 1.31 |
Rectangular Ducts
v, m/s at Q = 12000 m³/h — rows: height h, columns: width a
| h\a, mm | 50 | 100 | 150 | 200 | 250 | 300 | 350 | 400 | 450 | 500 | 550 | 600 | 650 | 700 | 750 | 800 | 850 | 900 | 950 | 1000 | 1200 | 1300 | 1400 | 1500 | 1600 | 1700 | 1800 | 1900 | 2000 | 2100 | 2200 | 2300 | 2400 | 2500 | 2600 | 2700 | 2800 | 2900 | 3000 | 3100 | 3200 | 3300 | 3400 | 3500 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 50 | 1333.3 | 666.7 | 444.4 | 333.3 | 266.7 | 222.2 | 190.5 | 166.7 | 148.1 | 133.3 | 121.2 | 111.1 | 102.6 | 95.2 | 88.9 | 83.3 | 78.4 | 74.1 | 70.2 | 66.7 | 55.6 | 51.3 | 47.6 | 44.4 | 41.7 | 39.2 | 37.0 | 35.1 | 33.3 | 31.7 | 30.3 | 29.0 | 27.8 | 26.7 | 25.6 | 24.7 | 23.8 | 23.0 | 22.2 | 21.5 | 20.8 | 20.2 | 19.6 | 19.0 |
| 100 | 666.7 | 333.3 | 222.2 | 166.7 | 133.3 | 111.1 | 95.2 | 83.3 | 74.1 | 66.7 | 60.6 | 55.6 | 51.3 | 47.6 | 44.4 | 41.7 | 39.2 | 37.0 | 35.1 | 33.3 | 27.8 | 25.6 | 23.8 | 22.2 | 20.8 | 19.6 | 18.5 | 17.5 | 16.7 | 15.9 | 15.2 | 14.5 | 13.9 | 13.3 | 12.8 | 12.3 | 11.9 | 11.5 | 11.1 | 10.8 | 10.4 | 10.1 | 9.8 | 9.5 |
| 150 | 444.4 | 222.2 | 148.1 | 111.1 | 88.9 | 74.1 | 63.5 | 55.6 | 49.4 | 44.4 | 40.4 | 37.0 | 34.2 | 31.7 | 29.6 | 27.8 | 26.1 | 24.7 | 23.4 | 22.2 | 18.5 | 17.1 | 15.9 | 14.8 | 13.9 | 13.1 | 12.3 | 11.7 | 11.1 | 10.6 | 10.1 | 9.7 | 9.3 | 8.9 | 8.5 | 8.2 | 7.9 | 7.7 | 7.4 | 7.2 | 6.9 | 6.7 | 6.5 | 6.3 |
| 200 | 333.3 | 166.7 | 111.1 | 83.3 | 66.7 | 55.6 | 47.6 | 41.7 | 37.0 | 33.3 | 30.3 | 27.8 | 25.6 | 23.8 | 22.2 | 20.8 | 19.6 | 18.5 | 17.5 | 16.7 | 13.9 | 12.8 | 11.9 | 11.1 | 10.4 | 9.8 | 9.3 | 8.8 | 8.3 | 7.9 | 7.6 | 7.2 | 6.9 | 6.7 | 6.4 | 6.2 | 6.0 | 5.7 | 5.6 | 5.4 | 5.2 | 5.1 | 4.9 | 4.8 |
| 250 | 266.7 | 133.3 | 88.9 | 66.7 | 53.3 | 44.4 | 38.1 | 33.3 | 29.6 | 26.7 | 24.2 | 22.2 | 20.5 | 19.0 | 17.8 | 16.7 | 15.7 | 14.8 | 14.0 | 13.3 | 11.1 | 10.3 | 9.5 | 8.9 | 8.3 | 7.8 | 7.4 | 7.0 | 6.7 | 6.3 | 6.1 | 5.8 | 5.6 | 5.3 | 5.1 | 4.9 | 4.8 | 4.6 | 4.4 | 4.3 | 4.2 | 4.0 | 3.9 | 3.8 |
| 300 | 222.2 | 111.1 | 74.1 | 55.6 | 44.4 | 37.0 | 31.7 | 27.8 | 24.7 | 22.2 | 20.2 | 18.5 | 17.1 | 15.9 | 14.8 | 13.9 | 13.1 | 12.3 | 11.7 | 11.1 | 9.3 | 8.5 | 7.9 | 7.4 | 6.9 | 6.5 | 6.2 | 5.8 | 5.6 | 5.3 | 5.1 | 4.8 | 4.6 | 4.4 | 4.3 | 4.1 | 4.0 | 3.8 | 3.7 | 3.6 | 3.5 | 3.4 | 3.3 | 3.2 |
| 350 | 190.5 | 95.2 | 63.5 | 47.6 | 38.1 | 31.7 | 27.2 | 23.8 | 21.2 | 19.0 | 17.3 | 15.9 | 14.7 | 13.6 | 12.7 | 11.9 | 11.2 | 10.6 | 10.0 | 9.5 | 7.9 | 7.3 | 6.8 | 6.3 | 6.0 | 5.6 | 5.3 | 5.0 | 4.8 | 4.5 | 4.3 | 4.1 | 4.0 | 3.8 | 3.7 | 3.5 | 3.4 | 3.3 | 3.2 | 3.1 | 3.0 | 2.9 | 2.8 | 2.7 |
| 400 | 166.7 | 83.3 | 55.6 | 41.7 | 33.3 | 27.8 | 23.8 | 20.8 | 18.5 | 16.7 | 15.2 | 13.9 | 12.8 | 11.9 | 11.1 | 10.4 | 9.8 | 9.3 | 8.8 | 8.3 | 6.9 | 6.4 | 6.0 | 5.6 | 5.2 | 4.9 | 4.6 | 4.4 | 4.2 | 4.0 | 3.8 | 3.6 | 3.5 | 3.3 | 3.2 | 3.1 | 3.0 | 2.9 | 2.8 | 2.7 | 2.6 | 2.5 | 2.5 | 2.4 |
| 450 | 148.1 | 74.1 | 49.4 | 37.0 | 29.6 | 24.7 | 21.2 | 18.5 | 16.5 | 14.8 | 13.5 | 12.3 | 11.4 | 10.6 | 9.9 | 9.3 | 8.7 | 8.2 | 7.8 | 7.4 | 6.2 | 5.7 | 5.3 | 4.9 | 4.6 | 4.4 | 4.1 | 3.9 | 3.7 | 3.5 | 3.4 | 3.2 | 3.1 | 3.0 | 2.8 | 2.7 | 2.6 | 2.6 | 2.5 | 2.4 | 2.3 | 2.2 | 2.2 | 2.1 |
| 500 | 133.3 | 66.7 | 44.4 | 33.3 | 26.7 | 22.2 | 19.0 | 16.7 | 14.8 | 13.3 | 12.1 | 11.1 | 10.3 | 9.5 | 8.9 | 8.3 | 7.8 | 7.4 | 7.0 | 6.7 | 5.6 | 5.1 | 4.8 | 4.4 | 4.2 | 3.9 | 3.7 | 3.5 | 3.3 | 3.2 | 3.0 | 2.9 | 2.8 | 2.7 | 2.6 | 2.5 | 2.4 | 2.3 | 2.2 | 2.2 | 2.1 | 2.0 | 2.0 | 1.9 |
| 550 | 121.2 | 60.6 | 40.4 | 30.3 | 24.2 | 20.2 | 17.3 | 15.2 | 13.5 | 12.1 | 11.0 | 10.1 | 9.3 | 8.7 | 8.1 | 7.6 | 7.1 | 6.7 | 6.4 | 6.1 | 5.1 | 4.7 | 4.3 | 4.0 | 3.8 | 3.6 | 3.4 | 3.2 | 3.0 | 2.9 | 2.8 | 2.6 | 2.5 | 2.4 | 2.3 | 2.2 | 2.2 | 2.1 | 2.0 | 2.0 | 1.9 | 1.8 | 1.8 | 1.7 |
| 600 | 111.1 | 55.6 | 37.0 | 27.8 | 22.2 | 18.5 | 15.9 | 13.9 | 12.3 | 11.1 | 10.1 | 9.3 | 8.5 | 7.9 | 7.4 | 6.9 | 6.5 | 6.2 | 5.8 | 5.6 | 4.6 | 4.3 | 4.0 | 3.7 | 3.5 | 3.3 | 3.1 | 2.9 | 2.8 | 2.6 | 2.5 | 2.4 | 2.3 | 2.2 | 2.1 | 2.1 | 2.0 | 1.9 | 1.9 | 1.8 | 1.7 | 1.7 | 1.6 | 1.6 |
| 650 | 102.6 | 51.3 | 34.2 | 25.6 | 20.5 | 17.1 | 14.7 | 12.8 | 11.4 | 10.3 | 9.3 | 8.5 | 7.9 | 7.3 | 6.8 | 6.4 | 6.0 | 5.7 | 5.4 | 5.1 | 4.3 | 3.9 | 3.7 | 3.4 | 3.2 | 3.0 | 2.8 | 2.7 | 2.6 | 2.4 | 2.3 | 2.2 | 2.1 | 2.1 | 2.0 | 1.9 | 1.8 | 1.8 | 1.7 | 1.7 | 1.6 | 1.6 | 1.5 | 1.5 |
| 700 | 95.2 | 47.6 | 31.7 | 23.8 | 19.0 | 15.9 | 13.6 | 11.9 | 10.6 | 9.5 | 8.7 | 7.9 | 7.3 | 6.8 | 6.3 | 6.0 | 5.6 | 5.3 | 5.0 | 4.8 | 4.0 | 3.7 | 3.4 | 3.2 | 3.0 | 2.8 | 2.6 | 2.5 | 2.4 | 2.3 | 2.2 | 2.1 | 2.0 | 1.9 | 1.8 | 1.8 | 1.7 | 1.6 | 1.6 | 1.5 | 1.5 | 1.4 | 1.4 | 1.4 |
| 750 | 88.9 | 44.4 | 29.6 | 22.2 | 17.8 | 14.8 | 12.7 | 11.1 | 9.9 | 8.9 | 8.1 | 7.4 | 6.8 | 6.3 | 5.9 | 5.6 | 5.2 | 4.9 | 4.7 | 4.4 | 3.7 | 3.4 | 3.2 | 3.0 | 2.8 | 2.6 | 2.5 | 2.3 | 2.2 | 2.1 | 2.0 | 1.9 | 1.9 | 1.8 | 1.7 | 1.6 | 1.6 | 1.5 | 1.5 | 1.4 | 1.4 | 1.3 | 1.3 | 1.3 |
| 800 | 83.3 | 41.7 | 27.8 | 20.8 | 16.7 | 13.9 | 11.9 | 10.4 | 9.3 | 8.3 | 7.6 | 6.9 | 6.4 | 6.0 | 5.6 | 5.2 | 4.9 | 4.6 | 4.4 | 4.2 | 3.5 | 3.2 | 3.0 | 2.8 | 2.6 | 2.5 | 2.3 | 2.2 | 2.1 | 2.0 | 1.9 | 1.8 | 1.7 | 1.7 | 1.6 | 1.5 | 1.5 | 1.4 | 1.4 | 1.3 | 1.3 | 1.3 | 1.2 | 1.2 |
| 850 | 78.4 | 39.2 | 26.1 | 19.6 | 15.7 | 13.1 | 11.2 | 9.8 | 8.7 | 7.8 | 7.1 | 6.5 | 6.0 | 5.6 | 5.2 | 4.9 | 4.6 | 4.4 | 4.1 | 3.9 | 3.3 | 3.0 | 2.8 | 2.6 | 2.5 | 2.3 | 2.2 | 2.1 | 2.0 | 1.9 | 1.8 | 1.7 | 1.6 | 1.6 | 1.5 | 1.5 | 1.4 | 1.4 | 1.3 | 1.3 | 1.2 | 1.2 | 1.2 | 1.1 |
| 900 | 74.1 | 37.0 | 24.7 | 18.5 | 14.8 | 12.3 | 10.6 | 9.3 | 8.2 | 7.4 | 6.7 | 6.2 | 5.7 | 5.3 | 4.9 | 4.6 | 4.4 | 4.1 | 3.9 | 3.7 | 3.1 | 2.8 | 2.6 | 2.5 | 2.3 | 2.2 | 2.1 | 1.9 | 1.9 | 1.8 | 1.7 | 1.6 | 1.5 | 1.5 | 1.4 | 1.4 | 1.3 | 1.3 | 1.2 | 1.2 | 1.2 | 1.1 | 1.1 | 1.1 |
| 950 | 70.2 | 35.1 | 23.4 | 17.5 | 14.0 | 11.7 | 10.0 | 8.8 | 7.8 | 7.0 | 6.4 | 5.8 | 5.4 | 5.0 | 4.7 | 4.4 | 4.1 | 3.9 | 3.7 | 3.5 | 2.9 | 2.7 | 2.5 | 2.3 | 2.2 | 2.1 | 1.9 | 1.8 | 1.8 | 1.7 | 1.6 | 1.5 | 1.5 | 1.4 | 1.3 | 1.3 | 1.3 | 1.2 | 1.2 | 1.1 | 1.1 | 1.1 | 1.0 | 1.0 |
| 1000 | 66.7 | 33.3 | 22.2 | 16.7 | 13.3 | 11.1 | 9.5 | 8.3 | 7.4 | 6.7 | 6.1 | 5.6 | 5.1 | 4.8 | 4.4 | 4.2 | 3.9 | 3.7 | 3.5 | 3.3 | 2.8 | 2.6 | 2.4 | 2.2 | 2.1 | 2.0 | 1.9 | 1.8 | 1.7 | 1.6 | 1.5 | 1.4 | 1.4 | 1.3 | 1.3 | 1.2 | 1.2 | 1.1 | 1.1 | 1.1 | 1.0 | 1.0 | 1.0 | 1.0 |
| 1100 | 60.6 | 30.3 | 20.2 | 15.2 | 12.1 | 10.1 | 8.7 | 7.6 | 6.7 | 6.1 | 5.5 | 5.1 | 4.7 | 4.3 | 4.0 | 3.8 | 3.6 | 3.4 | 3.2 | 3.0 | 2.5 | 2.3 | 2.2 | 2.0 | 1.9 | 1.8 | 1.7 | 1.6 | 1.5 | 1.4 | 1.4 | 1.3 | 1.3 | 1.2 | 1.2 | 1.1 | 1.1 | 1.0 | 1.0 | 1.0 | 0.9 | 0.9 | 0.9 | 0.9 |
| 1200 | 55.6 | 27.8 | 18.5 | 13.9 | 11.1 | 9.3 | 7.9 | 6.9 | 6.2 | 5.6 | 5.1 | 4.6 | 4.3 | 4.0 | 3.7 | 3.5 | 3.3 | 3.1 | 2.9 | 2.8 | 2.3 | 2.1 | 2.0 | 1.9 | 1.7 | 1.6 | 1.5 | 1.5 | 1.4 | 1.3 | 1.3 | 1.2 | 1.2 | 1.1 | 1.1 | 1.0 | 1.0 | 1.0 | 0.9 | 0.9 | 0.9 | 0.8 | 0.8 | 0.8 |
| 1300 | 51.3 | 25.6 | 17.1 | 12.8 | 10.3 | 8.5 | 7.3 | 6.4 | 5.7 | 5.1 | 4.7 | 4.3 | 3.9 | 3.7 | 3.4 | 3.2 | 3.0 | 2.8 | 2.7 | 2.6 | 2.1 | 2.0 | 1.8 | 1.7 | 1.6 | 1.5 | 1.4 | 1.3 | 1.3 | 1.2 | 1.2 | 1.1 | 1.1 | 1.0 | 1.0 | 0.9 | 0.9 | 0.9 | 0.9 | 0.8 | 0.8 | 0.8 | 0.8 | 0.7 |
| 1400 | 47.6 | 23.8 | 15.9 | 11.9 | 9.5 | 7.9 | 6.8 | 6.0 | 5.3 | 4.8 | 4.3 | 4.0 | 3.7 | 3.4 | 3.2 | 3.0 | 2.8 | 2.6 | 2.5 | 2.4 | 2.0 | 1.8 | 1.7 | 1.6 | 1.5 | 1.4 | 1.3 | 1.3 | 1.2 | 1.1 | 1.1 | 1.0 | 1.0 | 1.0 | 0.9 | 0.9 | 0.9 | 0.8 | 0.8 | 0.8 | 0.7 | 0.7 | 0.7 | 0.7 |
| 1500 | 44.4 | 22.2 | 14.8 | 11.1 | 8.9 | 7.4 | 6.3 | 5.6 | 4.9 | 4.4 | 4.0 | 3.7 | 3.4 | 3.2 | 3.0 | 2.8 | 2.6 | 2.5 | 2.3 | 2.2 | 1.9 | 1.7 | 1.6 | 1.5 | 1.4 | 1.3 | 1.2 | 1.2 | 1.1 | 1.1 | 1.0 | 1.0 | 0.9 | 0.9 | 0.9 | 0.8 | 0.8 | 0.8 | 0.7 | 0.7 | 0.7 | 0.7 | 0.7 | 0.6 |
| 1600 | 41.7 | 20.8 | 13.9 | 10.4 | 8.3 | 6.9 | 6.0 | 5.2 | 4.6 | 4.2 | 3.8 | 3.5 | 3.2 | 3.0 | 2.8 | 2.6 | 2.5 | 2.3 | 2.2 | 2.1 | 1.7 | 1.6 | 1.5 | 1.4 | 1.3 | 1.2 | 1.2 | 1.1 | 1.0 | 1.0 | 0.9 | 0.9 | 0.9 | 0.8 | 0.8 | 0.8 | 0.7 | 0.7 | 0.7 | 0.7 | 0.7 | 0.6 | 0.6 | 0.6 |
| 1700 | 39.2 | 19.6 | 13.1 | 9.8 | 7.8 | 6.5 | 5.6 | 4.9 | 4.4 | 3.9 | 3.6 | 3.3 | 3.0 | 2.8 | 2.6 | 2.5 | 2.3 | 2.2 | 2.1 | 2.0 | 1.6 | 1.5 | 1.4 | 1.3 | 1.2 | 1.2 | 1.1 | 1.0 | 1.0 | 0.9 | 0.9 | 0.9 | 0.8 | 0.8 | 0.8 | 0.7 | 0.7 | 0.7 | 0.7 | 0.6 | 0.6 | 0.6 | 0.6 | 0.6 |