1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Flow rate (CFM) in a different inlet are & outlet area

  1. Jul 27, 2012 #1
    Hello,

    Here are the knowns:
    Inlet open area = 17 inches^2
    Outlet open area = 30 inches^2
    Internal Fans = 270 cfm (3 fans @ 90 cfm each)

    What is the CFM through the system and what's the equations used to figure this out?

    Thanks a ton!
    John
     
  2. jcsd
  3. Jul 27, 2012 #2

    russ_watters

    User Avatar

    Staff: Mentor

    The answer appears to be given in the problem statement: 270 cfm.
     
  4. Jul 27, 2012 #3
    The fan spec is 90cfm per fan. That doesn't mean that 270cfm (3 fans) is what will exhaust out the rear of the unit. If I have a huge fan inside a box and a very little inlet or outlet, the fan will be choked and pressure will build due to the open air restriction.
     
  5. Jul 27, 2012 #4

    russ_watters

    User Avatar

    Staff: Mentor

    You'll need to look at fan curves and estimate pressure drop through your system then.

    Do you have a sketch you can upload?
     
    Last edited: Jul 27, 2012
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Flow rate (CFM) in a different inlet are & outlet area
  1. Flow rate and valves (Replies: 17)

  2. Flow rate (Replies: 18)

  3. Flow rate of sand (Replies: 1)

Loading...