HVAC Systems and Applications! - Resources, Tools and Basic Information for Engineering and Design.
Equivalent diameters for rectangular and circular ducts - air flows 100 - 50,000 CFM
Sponsored Links
The table below can be used to compare equivalent diameters for rectangular and round circular ducts.
| CFM
(Cubic Feet per Minute) |
Equivalent
Rectangular Duct Sizes (Inches) |
Equivalent Diameter
Round Duct Sizes (Inches) |
| 100 | 3 X 4 | 4 |
| 200 | 3 X 7
4 X 5 |
5 |
| 300 | 4 X 7
5 X 6 |
6 |
| 400 | 4 X 9
5 X 7 6 X 6 |
7 |
| 500 | 6 X 7 | 8 |
| 750 | 5 X 12
6 X 10 7 X 8 |
9 |
| 1000 | 7 X 10
8 X 9 |
10 |
| 1250 | 8 X 10
9 X 9 |
10 |
| 1500 | 8 X 12
10 X 10 |
12 |
| 1750 | 8 X 14
9 X 12 10 X 11 |
12 |
| 2000 | 8 X 15
10 X 12 |
12 |
| 2500 | 10 X 14
12 X 12 |
14 |
| 3000 | 12 X 14 | 14 |
| 3500 | 12 X 15 | 15 |
| 4000 | 10 X 22
14 X 15 |
16 |
| 4500 | 12 X 19
14 X 16 |
17 |
| 5000 | 10 X 25
12 X 20 15 X 16 |
17 |
| 6000 | 14 X 20
15 X 18 |
19 |
| 7000 | 12 X 26
16 X 20 |
20 |
| 8000 | 12 X 30
14 X 25 |
21 |
| 9000 | 12 X 34
15 X 25 |
22 |
| 10000 | 12 X 36
16 X 25 20 X 20 |
23 |
| 12500 | 12 X 45
16 X 30 20 X 24 |
24 |
| 15000 | 16 X 36
18 X 30 23 X 25 |
26 |
| 17500 | 16 X 40
20 X 32 25 X 25 |
28 |
| 20000 | 16 X 45
20 X 35 25 X 28 |
30 |
| 25000 | 16 X 55
20 X 43 25 X 38 |
32 |
| 30000 | 20 X 50
30 X 32 |
34 |
| 35000 | 20 X 55
30 X 35 |
36 |
| 40000 | 25 X 48
30 X 40 |
38 |
| 45000 | 25 X 25
32 X 40 |
40 |
| 50000 | 32 X 45
35 X 40 |
42 |
Sponsored Links
Difficult to find your favorite ToolBox page? Add a link to the page in your own personal Shortlist!
Translate this page to
Spanish
French
German
Italian
Dutch
Norwegian
© The HVAC ToolBox
The content in The HVAC ToolBox is copyrighted but can be used with NO WARRANTY or LIABILITY. Important information should always be double checked with alternative sources. All applicable national and local regulations and practices concerning this aspects must be strictly followed and adhered to.
We appreciate any comments and tips on how to make The HVAC ToolBox a better information source. Please contact us by email if You find any faults, inaccurate, or otherwise unacceptable information.
5 12 1
View Engineering, Design and Construction news in the absolute FREE Automatic WebSite Viewer. Engineering Breaking News!
