[labnetwork] pressure independent valves on exhaust?

[Morrison, Richard H., Jr.]

We use blast gates, they just block the duct and they are pinned to get a flow that allows the 100 fpm at the face of the hood. So we have maximum exhaust 24 hours per day.

We were going to use variable exhaust dampers on the duct work so that we could close the hood sash at night time to save $$. The upfront cost of the dampers and control system upgrade was high and the payback time period to long to justify the expense. Now we are stuck with a wasteful operation. It is very difficult to retrofit the systems due to lack of room to modify the duct work. So add the dampers and control software up front and it saves you many $$ in operating cost.

Rick


-----Original Message-----
From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu] On Behalf Of Iulian Codreanu
Sent: Wednesday, April 23, 2014 9:08 AM
To: Fab Network
Subject: [labnetwork] pressure independent valves on exhaust?

Good Morning.

Do you have "pressure-independent" valves on the exhaust of the cleanroom equipment (wet benches included)?  If you do not, what were the reasons and what do you use instead?

Thank you very much.

Iulian

--
iulian Codreanu, Ph.D.
Director of Operations, UD NanoFab
University of Delaware
163 ISE Lab
221 Academy Street
Newark, DE 19716
302-831-2784


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