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<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">HMNTL invested in a PSA that went online in July 2024. The LN₂ portion of the system paid for itself within a year. Prior to that, HMNTL was spending about $350,000 annually on
LN₂ expenses. As part of the upgrade, we also replaced our air compressor with a variable-speed, oil-free unit. If you upgrade to a PSA, you will most likely be required to use an oil-free compressor. The advantage of this is that it gives you the flexibility
to run either CDA or N₂, depending on your needs.<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">We have recently begun transitioning back to CDA on systems that were previously plumbed with N₂, primarily due to oil and water contamination concerns.<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Based on our experience, I strongly recommend that any facility currently using LN₂ as a purge gas consider investing in a PSA. Smaller units, such as the DB-5 or DB-10, can easily
handle the demands of most small labs while eliminating the need for bulk deliveries.<o:p></o:p></p>
<p class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto">Just my two cents.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><b><span style="font-size:11.0pt;color:#002060;text-transform:uppercase">Deon D. Collins<o:p></o:p></span></b></p>
<p class="MsoNormal"><b><span style="font-size:11.0pt;color:#002060;text-transform:uppercase"><o:p> </o:p></span></b></p>
<p class="MsoNormal"><span style="font-size:11.0pt;color:#002060"><br>
<i>Director of Facilities<o:p></o:p></i></span></p>
<p class="MsoNormal"><i><span style="font-size:11.0pt;color:#002060">The Grainger College Of Engineering UIUC</span></i><span style="font-size:11.0pt;color:#002060"><br>
</span><span style="font-size:11.0pt;color:#002060">Holonyak Micro & Nanotechnology Lab</span><span style="font-size:11.0pt;color:#1F497D"><br>
</span><span style="font-size:11.0pt;color:#13294B">208 N Wright St Rm. 1114 | MC-249</span><span style="font-size:11.0pt;color:#1F497D"><br>
</span><span style="font-size:11.0pt;color:#13294B">Urbana, IL 61801</span><span style="font-size:11.0pt;color:#1F497D"><br>
</span><span style="font-size:11.0pt;color:#13294B">217-300-7531 | </span><span style="font-size:11.0pt;color:#1F497D"><a href="mailto:deonc69@illinois.edu"><span style="color:#0563C1">deonc69@illinois.edu</span></a><br>
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</span><a href="http://illinois.edu/"><span style="font-size:11.0pt;color:#1F497D;text-decoration:none"><img border="0" width="119" height="21" style="width:1.2395in;height:.2187in" id="Picture_x0020_1" src="cid:image001.png@01DC2932.1C57C510"></span></a><span style="font-size:11.0pt;color:#1F497D"><br>
<br>
</span><i><span style="font-size:11.0pt;color:#666666">Under the Illinois Freedom of Information Act any written communication to or from university employees regarding university business is a public record and may be subject to public disclosure.
</span></i><span style="font-size:11.0pt;color:#002060"><o:p></o:p></span></p>
<p class="MsoNormal"><u><span style="font-size:11.0pt;color:#1F497D"><o:p><span style="text-decoration:none"> </span></o:p></span></u></p>
<p class="MsoNormal"><b><span style="font-size:10.0pt;color:#A3238B">Life begins at the end of your comfort zone. <o:p></o:p></span></b></p>
<p class="MsoNormal"><b><span style="font-size:10.0pt;color:#A3238B"> Propeck Amanda<o:p></o:p></span></b></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> labnetwork <labnetwork-bounces@mtl.mit.edu>
<b>On Behalf Of </b>Danny Pestal<br>
<b>Sent:</b> Thursday, September 18, 2025 7:14 PM<br>
<b>To:</b> Carsen Kline <carsen@stanford.edu><br>
<b>Cc:</b> Labnetwork (labnetwork@mtl.mit.edu) <labnetwork@mtl.mit.edu>; Schmidt, Benjamin Willis <ben.w.schmidt@vanderbilt.edu><br>
<b>Subject:</b> Re: [labnetwork] Recommendations to reduce lab nitrogen usage<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Since Bob Hamilton wrote that entry to the Labnet, UC Berkeley decided to extend the replacement of the nitrogen purge on vacuum pumps to our etch tools as well. We felt confident doing this since we are very diligent in the upkeep of our
CDA dryer and run it at a very low dew point such that the ppm of water in our CDA is lower than the moisture created in a lot of the etch processes. Everyone was convinced we would end up with a bunch of rusted out vacuum pumps and/or exhaust lines but we
haven't had any issues at all. In 2013, prior to adding the etch tools, this was saving us upwards of $50,000 a year, I'm sure it's more now. <o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">More recently we installed a nitrogen generator to provide low quality nitrogen (99.5% - 99.99%) in places where "process" level nitrogen wasn't required. I don't have any savings data from this yet as we've been overly busy and haven't
plumbed the system out to the tools yet. We expect the savings to be SIGNIFICANT.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Future plans are to add even more nitrogen generation, but at that point we'll have to look into an upgrade of our air compressors.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Danny Pestal<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Equipment & Facilities Manager <o:p></o:p></p>
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<p class="MsoNormal">UC Berkeley NanoLab<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">510-809-8600<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">On Thu, Sep 18, 2025, 4:47<span style="font-family:"Arial",sans-serif"> </span>PM Carsen Kline <<a href="mailto:carsen@stanford.edu" target="_blank">carsen@stanford.edu</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black">Hi Ben,<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black">Here at Stanford we just moved to a nitrogen generator in July. We're now filling our 9000 gallon liquid tank every five weeks instead of every five days. So if you can convince the
powers that be to pay for it (major savings in operating costs), and if your overhead dollars pay the electricity, it's the greatest thing ever. We've kept our tank in place to keep feeding our branch of purified process nitrogen, and it serves as automatic
backup in case the generator shuts down. <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black">Before the generator, we were looking for ways to automate nitrogen cuts to our vacuum pumps during idle times. I inherited a control panel from a fab surplus sale that uses a PLC
and solenoid valves to reduce N2 flow after x minutes using a signal tied to the NEMO interlock. I can provide full details or even a partially built panel if you like. <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black">We're using CDA for all of our gas cabinet headcase purges (we were able to justify it with our jurisdiction because there are sprinklers in the cabinets) and acid wet bench headcase
purge. <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black">You can also get away purging some of your vacuum pumps using CDA instead of N2. I refer you to a thread on the labnetwork archives:<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black"><a href="https://urldefense.com/v3/__https:/mtl.mit.edu/pipermail/labnetwork/2013-September/001033.html__;!!DZ3fjg!6jLgXjzxPIqtzWX5PK3es0jyTLOj5kC42yG6s3YVIu8A2zBcKUl_3JMG7vneoqmD97-dBhh6tuDm80hJluzED7ax6oQ$" target="_blank">https://mtl.mit.edu/pipermail/labnetwork/2013-September/001033.html</a><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black">Or try a search like "Show me threads about using CDA in lieu of N2" on nanobot.chat to go deeper into the Labnetwork archives.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black">Happy to share more offline if you like.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black">All the best,<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black">Carsen<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black">Carsen Kline<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black">Lab Operations Manager<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black">Stanford Nanofabrication Facility<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black">650-724-8214<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Arial",sans-serif;color:black"><a href="https://urldefense.com/v3/__http:/snfexfab.stanford.edu__;!!DZ3fjg!6jLgXjzxPIqtzWX5PK3es0jyTLOj5kC42yG6s3YVIu8A2zBcKUl_3JMG7vneoqmD97-dBhh6tuDm80hJluzEDFcqnLI$" target="_blank">snfexfab.stanford.edu</a><o:p></o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:black">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:black"> labnetwork <<a href="mailto:labnetwork-bounces@mtl.mit.edu" target="_blank">labnetwork-bounces@mtl.mit.edu</a>>
on behalf of Schmidt, Benjamin Willis <<a href="mailto:ben.w.schmidt@Vanderbilt.Edu">ben.w.schmidt@Vanderbilt.Edu</a>><br>
<b>Sent:</b> Thursday, September 18, 2025 10:05 AM<br>
<b>To:</b> Labnetwork (<a href="mailto:labnetwork@mtl.mit.edu" target="_blank">labnetwork@mtl.mit.edu</a>) <<a href="mailto:labnetwork@mtl.mit.edu" target="_blank">labnetwork@mtl.mit.edu</a>><br>
<b>Subject:</b> [labnetwork] Recommendations to reduce lab nitrogen usage</span> <o:p>
</o:p></p>
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<p class="MsoNormal"> <o:p></o:p></p>
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<p class="MsoNormal"><span style="color:black">Hello Labnetwork,<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="color:black">In our nanofab at Vanderbilt, we are looking at ways to reduce our nitrogen usage, and I wanted to ask for any recommendations, success stories, or failures that might help in our search.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="color:black">For background, we use 5N “house” N2 for purging catastrophic scrubbers, point-of-use scrubbers, gas cabinets, VMBs, and some vacuum pumps 24/7. Additionally, we have on-demand usage at wet chemical hoods and
various tools, but the most significant users are the constant-purge items listed above.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="color:black">Our N2 is supplied from a large tank next to our building that is periodically filled from a truck to provide 5N “house” nitrogen, and then we have a set of purifiers to give us 6N “process” nitrogen for specific
tools. This was part of an original design for flexibility with future lab growth.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="color:black">We’re already trying to cut back on the on-demand needs and only turning hoods on and off as needed for example, but we don’t really have the same options for the gas delivery and abatement systems.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="color:black">We’re also looking at ideas such as a hybrid approach like putting the scrubbers onto a nitrogen generator that may not need the same purity requirements, but this is a new area for us.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="color:black">I can provide specific usage numbers privately if it helps, but we are a nominally 10,000 sqft facility (half under filtration, half service areas).<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="color:black">Thanks for any suggestions!<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="color:black">Ben<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="color:black"><o:p> </o:p></span></p>
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<p style="margin:0in;mso-line-height-alt:11.8pt;background:white"><span style="font-size:13.5pt;font-family:"Segoe UI",sans-serif;color:black">Ben W. Schmidt, Ph.D.</span><o:p></o:p></p>
<p style="margin:0in;line-height:11.8pt;background:white"><span style="font-size:10.5pt;font-family:"Segoe UI",sans-serif;color:black">Cleanroom Manager<br>
Vanderbilt Institute of Nanoscale Science and Engineering</span><o:p></o:p></p>
<p style="margin:0in;line-height:11.8pt;background:white"><span style="font-size:10.5pt;font-family:"Segoe UI",sans-serif;color:black">Vanderbilt University, Nashville, TN</span><o:p></o:p></p>
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<p class="MsoNormal">_______________________________________________<br>
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