×
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

minimum air velocity to maintain +ve pressure for a retail shop design

minimum air velocity to maintain +ve pressure for a retail shop design

minimum air velocity to maintain +ve pressure for a retail shop design

(OP)
I would like to know what the minimum air velocity should be to maintain positive pressure at the entrance of a typical retail shop in a big shopping mall

I know positive pressure would occur as long as the supply air rate is larger than the return air. However, is there any standard/ guideline that can be used as a reference?

What i have found is all about cleanroom, smoke extraction system design in which the requirement is too unrealistic for a retail shop..

Please help.

RE: minimum air velocity to maintain +ve pressure for a retail shop design

Won't you be at the mercy of the mall's ventilation system? I would be tempted to try a differential-pressure control, maybe try to attain 0.01-0.03" W.C. with some sort of variable control of your store's ventilation air. You'll need a good sensor, well-chosen sensing points, and damping of some sort.

OR, stop by a local mall and see what Abercrombie & Fitch does. Every instance of A&F I have ever seen makes the mall area outside their store stink to high heaven.

OR, wait for one of the more experienced HVAC engineers to respond (I'm more of a controls guy).  There's probably someone here who has crossed this obstacle before.

Good on ya,

Goober Dave

RE: minimum air velocity to maintain +ve pressure for a retail shop design

Any detectable velocity outward through the opening is enough to create differential pressure.

I think Bernoulli's Law might be what you are looking for.  

RE: minimum air velocity to maintain +ve pressure for a retail shop design

(OP)
Thanks for the replies

I was asked to find the exact figures that have been stated in any standard/guideline like ASHRAE, CIBSE.etc to meet the requirement for positive pressure .

Its often said that positive pressure shall be maintained but there shall be different requirements for each application.

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