Engineering ToolBox - Resources, Tools and Basic Information for Engineering and Design of Technical Applications!

Sizing Circular Ducts

A rough guide to maximum air volume capacity of circular ducts in comfort, industrial and high speed ventilation systems.

Maximum air velocity in the ducts should be kept below certain limits to avoid unacceptable noise generation.

ductwork velocity method

The values from the table below can be used for rough sizing of ducts in comfort, industrial and high speed ventilation systems.

For full table with Industrial and High Speed Systems - rotate the screen!

Sizing Circular Ducts

Diameter
(mm)
Area
(m2)
Maximum Air Volume Flow (m3/h)
Comfort systemsIndustrial systemsHigh speed systems
Main ducts Secondary ducts Connecting ducts Main ducts Secondary ducts Connecting ducts Main ducts Secondary ducts Connecting ducts
Speed (m/s)
5.5 4 2 10 6.5 4 14 9 6.5
63 0.003 62 45 22 112 73 45 157 101 73
80 0.005 99 72 36 181 118 72 253 163 118
100 0.008 155 113 57 283 184 113 396 254 184
125 0.012 243 177 88 442 287 177 618 397 287
160 0.020 398 289 145 723 470 289 1013 651 470
200 0.031 622 452 226 1130 735 452 1583 1017 735
250 0.049 971 707 353 1766 1148 707 2473 1590 1148
315 0.078 1542 1122 561 2804 1823 1122 3926 2524 1823
400 0.126 2487 1809 904 4522 2939 1809 6330 4069 2939
500 0.196 3886 2826 1413 7065 4592 2826 9891 6359 4592
630 0.312 6169 4487 2243 11216 7291 4487 15703 10095 7291
800 0.502 9948 7235 3617 18086 11756 7235 25321 16278 11756
1000 0.785 15543 11304 5652 28260 18369 11304 39564 25434 18369
1250 1.227 24286 17663 8831 44156 28702 17663 61819 39741 28702

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

Search

Search is the most efficient way to navigate the Engineering ToolBox.

Engineering ToolBox - SketchUp Extension - Online 3D modeling!

3D Engineering ToolBox Extension to SketchUp - add parametric components to your SketchUp model

Add standard and customized parametric components - like flange beams, lumbers, piping, stairs and more - to your Sketchup model with the Engineering ToolBox - SketchUp Extension - enabled for use with older versions of the amazing SketchUp Make and the newer "up to date" SketchUp Pro . Add the Engineering ToolBox extension to your SketchUp Make/Pro from the Extension Warehouse !

Translate this Page

Translate this page to Your Own Language .

About the Engineering ToolBox!

Privacy Policy

We don't collect information from our users. More about

We use a third-party to provide monetization technologies for our site. You can review their privacy and cookie policy here.

You can change your privacy settings by clicking the following button: .

Citation

This page can be cited as

  • The Engineering ToolBox (2003). Sizing Circular Ducts. [online] Available at: https://www.engineeringtoolbox.com/circular-ducts-sizing-d_206.html [Accessed Day Month Year].

Modify the access date according your visit.

3D Engineering ToolBox - draw and model technical applications! 2D Engineering ToolBox - create and share online diagram drawing templates! Engineering ToolBox Apps - mobile online and offline engineering applications!

Unit Converter

















































5.16.12

.