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Mac,<br>
Our EH&S treats our wet benches as fume hoods<br>
and requires face velocity of at least 100 feet per minute.<br>
100 - 150 fpm is considered satisfactory.<br>
<br>
Several groups have been pushing for improved hood design<br>
to bring air flow requirements down to 60fpm.<br>
Lawrence Berkeley Lab has an extensive program in this area:<br>
<a class="moz-txt-link-freetext" href="http://ateam.lbl.gov/hightech/fumehood/fhood.html">http://ateam.lbl.gov/hightech/fumehood/fhood.html</a><br>
A summary report of "The Berkeley Hood" (not hoodie) is here:<br>
<a href="http://ateam.lbl.gov/hightech/fumehood/Publications.html">http://ateam.lbl.gov/hightech/fumehood/Publications.html</a><br>
<br>
Bottom Line - with improved hood design you can definitely<br>
decrease exhaust requirements and achieve significant savings.<br>
But it would not be prudent to just decrease the face velocity <br>
requirement and use that new lower standard with legacy equipment.<br>
If a new (decreased) standard is defined it will only apply to<br>
new equipment that meets a specific design requirement.<br>
<br>
Bill Flounders<br>
UC Berkeley NanoLab<br>
<br>
<br>
<br>
Mac Hathaway wrote:
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<font face="Times New Roman, Times, serif">Hey all,<br>
<br>
What do folks currently consider satisfactory regarding the
air-flow face velocity at their fume hoods and wet benches? Do
you have any ASHRAE/ANSI/SEMI-type standards or references that
you draw on for this purpose?<br>
<br>
The topic came up today in the context of energy savings, lab
make-up air, and this sort of thing...<br>
<br>
<br>
Thanks,<br>
<br>
Mac Hathaway<br>
Harvard Center for Nanoscale Systems<br>
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