Water velocity in water header

[wilsoncheung]

Hello, guys!

Do you know what velocity in water header is suitable?

I'm talking about the water header of Air-Cooling and Dehumidifying Coils.

From ASHRAE, we know the water velocity inside the tube is about 0.3-2.4m/s, but ASHRAE doesn't tell us about the velocity range of the water header. What's you opion?

Thank you!

[Brian_UK]

I wont go into all the variations to this answer but will point you towards this e-book.

http://www.haestad.com/library/books/awdm/online/wwhelp/wwhimpl/js/html/wwhelp.htm

Click on the index and then the letter "V" for velocity, select What is Maximum.....

[wilsoncheung]

This book is gorgeous！Thank you very much, Brian! I find my answer.

It's a pity that I can't download this book.:)

[MilosBog]

Generally, the water velocity in header should be 0.2-0.3m/s. But,i use this kind of sizing only for main header. For instance, if you use the underfloor cooling with the manifolds, than it depends of the valves on it..For what do you need it exactly? Be careful regarding this stuff, it is just a piece of pipe but it has a great influence on the system..