[labnetwork] Combined or separate exhaust?

[Nicholas Menounos]

Hi Travis,

Many considerations: cost, code, feasibility, resiliency, scale etc. Too much to put in email, but I found this book is excellent (https://www.amazon.com/Semiconductor-Industry-Wafer-Exhaust-Management-ebook/dp/B07L6TKLXQ)

In general, the larger your facility the more it makes sense to segregate...Fabs often have several flavors (acid, solvent/VOC, heat, ammonia, perchloric, silane, gas cabinets etc). If your air permit requires (or you want to enable) centralized scrubbers in the future, low concentrations and incompatible material mixing becomes a design constraint the pushes you towards separation.

Search the labnetwork archives, as this has come up in the past with great responses from the community...If you proceed with a combination system, the design team should conduct a risk assessment to document process assumptions. You want to tell them your needs up front, not be told what can be accommodated after its built.

Best,
Nicholas Menounos, PE, LEED AP
Associate Director of Infrastructure

MIT.nano
Massachusetts Institute of Technology
77 Massachusetts Ave, Bldg 12-5007
Cambridge, MA 02139
Cell: (508) 932-0938<tel:+15089320938>
Office: (617) 253-7234<tel:+16172537234>
Email: Menounos at mit.edu<mailto:Menounos at mit.edu>

From: labnetwork <labnetwork-bounces at mtl.mit.edu> On Behalf Of Massey, Travis
Sent: Monday, February 24, 2025 9:24 PM
To: labnetwork at mtl.mit.edu
Subject: [labnetwork] Combined or separate exhaust?

Hi all,

LLNL is planning a significant cleanroom expansion, and the question arose whether we need separate exhaust for hoods and tools/gases, or if they can be combined into a single shared exhaust.  Or do you have a single exhaust with 2+ exhaust fans pulling simultaneously, so there's always some exhaust air moving if one fan is down?  The conventional wisdom around here has its share of holes, so I'm out to learn from the broader nanofab cleanroom community.  How are your cleanrooms' exhaust systems are configured, especially if you've had to go down this cleanroom design rabbit hole?

I'm also broadly open any other lessons learned regarding provisioning exhaust or other utilities - whatever you feel like sharing.  Too much information during the design phase is far better than too little.

Thanks,
Travis Massey
Center for Micro and Nano Technology (CMNT)
Lawrence Livermore National Laboratory (LLNL)
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