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<p class="MsoNormal"><a name="x__MailAutoSig"><span style="font-size:11.0pt">Hi Joe,<o:p></o:p></span></a></p>
<p class="MsoNormal"><span style="mso-bookmark:x__MailAutoSig"><span style="font-size:11.0pt"><o:p> </o:p></span></span></p>
<p class="MsoNormal"><span style="mso-bookmark:x__MailAutoSig"><span style="font-size:11.0pt">I have never seen powder coated Al duct in large sizes, but my intuition is that it would rival installed cost of SS.<o:p></o:p></span></span></p>
<p class="MsoNormal"><span style="mso-bookmark:x__MailAutoSig"><span style="font-size:11.0pt"><o:p> </o:p></span></span></p>
<p class="MsoNormal"><span style="mso-bookmark:x__MailAutoSig"><span style="font-size:11.0pt">Galvanized is the most common return air material in industry (nano returns are G-90 = extra thick coat), but we only have ducted returns in the ISO7 spaces (main
cleanroom is open plenum).<o:p></o:p></span></span></p>
<p class="MsoNormal"><span style="mso-bookmark:x__MailAutoSig"><span style="font-size:11.0pt"><o:p> </o:p></span></span></p>
<p class="MsoNormal"><span style="mso-bookmark:x__MailAutoSig"><span style="font-size:11.0pt">For areas with significant corrosive chemical quantities and high likelihood of spills (e.g. wet etching bays), I would consider 316SS upgrade (esp if the duct is
buried) to future proof. Potential for zinc salts/corrosion particles that reduce HEPA life is low, but we often lack funding and detection methods post occupancy…Limiting the upgrade to wet bays, significantly reduces scope.<o:p></o:p></span></span></p>
<p class="MsoNormal"><span style="mso-bookmark:x__MailAutoSig"><span style="font-size:11.0pt"><o:p> </o:p></span></span></p>
<p class="MsoNormal"><span style="mso-bookmark:x__MailAutoSig"><span style="font-size:11.0pt">Best,<o:p></o:p></span></span></p>
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<p class="MsoNormal" style="background:white"><span style="mso-bookmark:x__MailAutoSig"><b><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">Nick Menounos, </span></b></span><span style="mso-bookmark:x__MailAutoSig"></span><span style="font-size:10.0pt;font-family:"Arial",sans-serif;color:black">PE</span><o:p></o:p></p>
<p class="MsoNormal" style="background:white"><span style="font-size:9.0pt;font-family:"Arial",sans-serif;color:black">MIT.nano - Associate Director of Infrastructure</span><o:p></o:p></p>
<p class="MsoNormal" style="background:white"><span style="font-size:9.0pt;font-family:"Arial",sans-serif;color:black">Cell: </span><span style="color:black"><a href="tel:+15089320938"><span style="font-size:9.0pt;font-family:"Arial",sans-serif;color:blue">(508)
932-0938</span></a></span><o:p></o:p></p>
<p class="MsoNormal" style="background:white"><span style="font-family:"Calibri",sans-serif;color:black"> </span><span style="font-size:11.0pt"><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">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>Joseph Losby<br>
<b>Sent:</b> Monday, May 4, 2026 12:50 PM<br>
<b>To:</b> Lab Network (labnetwork@mtl.mit.edu) <labnetwork@mtl.mit.edu><br>
<b>Subject:</b> [labnetwork] Galvanized steel for air-return surfaces<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"><span style="font-size:11.0pt;color:black">Hello Labnetwork, <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;color:black">We are designing an ISO 5 facility using a bay-and-chase layout. Do you recommend the use of galvanized steel for recirculating air-return surfaces (only), specifically regarding long term risks
of zinc oxide shedding or oxidation? All air return is refiltered before entering the cleanroom. <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;color:black">Would powder-coated aluminum be a better option? Although stainless steel would be used for the ducting between the AHUs and cleanroom HEPA filters (as well as all exhausts), the use of galvanized
upstream is mainly a value engineering consideration.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;color:black">Cheers,<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;color:black">Joe<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;color:black"><o:p> </o:p></span></p>
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<p class="elementtoproof" style="background:white"><b><span style="font-size:10.0pt;font-family:"Calibri",sans-serif;color:#D6001C">Joseph Losby, PhD</span></b><o:p></o:p></p>
<p class="elementtoproof" style="background:white"><b><span style="font-size:10.0pt;font-family:"Calibri",sans-serif;color:black;background:white">Manager, qLab Operations</span></b><o:p></o:p></p>
<p class="elementtoproof" style="background:white"><b><span style="font-size:10.0pt;font-family:"Calibri",sans-serif;color:#C82613;background:white">Quantum City, Office of the VPR</span></b><o:p></o:p></p>
<p class="elementtoproof" style="background:white"><b><span style="font-size:10.0pt;font-family:"Calibri",sans-serif;color:black"><a href="mailto:joseph.losby@ucalgary.ca">joseph.losby@ucalgary.ca</a></span></b><o:p></o:p></p>
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