Ventilation Systems - Return Intakes
Capacities of air return intakes:
Nominal Size (in x in) | Approximately Capacity (cfm) |
---|---|
10 x 4 | 100 |
10 x 5 | 125 |
10 x 6 | 155 |
10 x 8 | 215 |
12 x 4 | 120 |
12 x 5 | 155 |
12 x 6 | 190 |
12 x 8 | 260 |
12 x 10 | 325 |
14 x 4 | 145 |
14 x 5 | 180 |
14 x 6 | 220 |
14 x 8 | 305 |
24 x 4 | 260 |
24 x 5 | 320 |
24 x 6 | 390 |
24 x 8 | 490 |
24 x 10 | 665 |
24 x 12 | 795 |
30 x 4 | 300 |
30 x 5 | 400 |
30 x 6 | 485 |
30 x 8 | 660 |
30 x 10 | 830 |
30 x 12 | 1015 |
30 x 14 | 1160 |
30 x 16 | 1355 |
Screen Efficiency
The free intake area will be reduced by an insect or bird screen.
- 1/2" mesh screen -> 90% free area
- 1/4" mesh screen -> 80% free area
- insect screen -> 50% free area
Related Topics
• Ventilation Systems
Design of systems for ventilation and air handling - air change rates, ducts and pressure drops, charts and diagrams and more.
Related Documents
Air Intakes and Outlets
Ventilation systems - air intakes and outlets - rules of thumbs.
Mesh Sizes vs. Particle Diameters
Strainers and filters - mesh size vs. particle diameter opening size.
Velocity Classification of Ventilation Ducts
Recommended air velocities in ventilation ducts