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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Please clarify whether you are referring to the pre-filters Upstream of the air handlers) or the actual HEPA filters in the ceiling downstream from the air
handlers. In my experience, HEPA’s are never replaced. The best way to determine if the HEPA’s are struggling is to compare the motor amperage draw on the VFD’s with a baseline to the present readings. You must of course, run the motors at the same speed for
comparison. If the filters are struggling, the amperage will be lower for a given speed, sort of like a shop vac when the inlet is clogged.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Steve Paolini<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Principal Equipment Engineer<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Harvard University Center for Nanoscale Systems<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D">11 Oxford St.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Cambridge, MA 02138<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D">617- 496- 9816<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D">spaolini@cns.fas.harvard.edu<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D">www.cns.fas.harvard.edu</span><span style="font-size:14.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p></o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> labnetwork-bounces@mtl.mit.edu [mailto:labnetwork-bounces@mtl.mit.edu]
<b>On Behalf Of </b>Jasper Nijdam<br>
<b>Sent:</b> Tuesday, April 10, 2018 1:16 PM<br>
<b>To:</b> labnetwork@mtl.mit.edu<br>
<b>Subject:</b> [labnetwork] Filter replacement inside the lab<o:p></o:p></span></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt">Heho All,<o:p></o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt">Our HEPA filters are mounted such that we have to replace them from the inside of the lab. Can anybody share an SOP on how to do this while minimizing the amount of dust polluting the lab?<o:p></o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt">Also, while I have your attention: Does anybody know a reliable repair service for our very old Dektak 3030?<o:p></o:p></p>
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<p class="MsoNormal">Thanks,<br clear="all">
<o:p></o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt">Jasper Nijdam<br>
Technical Manager GNuLab, Georgetown University<o:p></o:p></p>
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