Re: maximum duct velocity

The maximum velocity you can take in a duct is when the duct pressure loss just equals the fan head - this can be as high as you like, up to sonic velocity. In practice, most main ducts have velocities in the range 40-75 ft/sec. As the duct diameter increases, the velocity can be increased because the wall area decreases as a ratio to the cross section (less friction),
BUT, in certain parts of a system, the velocity may be as low as 15 ft/sec, or as high as 150 ft/sec. Other factors that affect the 'maximum' velocity are the type of gas and its density.
Neil

At 04:47 PM 5/15/2001 +0530, you wrote:
>I have little problem in Duct velocity. For a given I.D. fan what will be
>the maximum velocity we can take in Duct. What is the limiting factor of
>duct velocity according to fan design.
>Regards
>Hitesh
Received on Tue May 15 13:39:00 2001