×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Fan in series

Fan in series

Fan in series

(OP)
Fans in series

I have a fan coil unit with about 210pa exteranl static pressure on it (pretty low). I am low in available pressure and the fan is to do both supply and return duct (100% recirc)

To help the situation I am putting a return air fan in the return air duct from the returan air grilles to a box at the back of the fan coil unit.
Is it ok to run two fans in series even if they are different fan curves. The return air fan will have a variable speed drive on it to match the suplly air fan.

RE: Fan in series

No problems as long as you maintain the return fan flowrate equal to that of supply fan. Ideally, the return fan should be selected at the supply fan cfm and at a static pressure equal to the total SP required minus the external static of supply fan.

RE: Fan in series

If the fans are either axial or forward-curved blades and the fan curve has a bump, you will get some interesting aerodynamic effects unless the fans are exactly the same and start simultaneously.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources