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

[soilyyy]

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.

 

[DRWeig]

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

 

[IRstuff]

Is this for school? This identical question has come up in the last 6 months.

TTFN

FAQ731-376
Chinese prisoner wins Nobel Peace Prize

 

[mauricestoker]

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.

 

[soilyyy]

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.