Fume hoods in higher education

[gfoote2]

Hello Everyone,

I hope you are taking time to enjoy family, good weather and summer fun!
I am preparing for my middle daughters wedding next weekend.  

We would like to know what our peers are doing to help construct the most helpful presentation this fall. 

At this time, we are looking for quick off the cuff answers  for what other universities are doing to manage fume hoods on your campus’. (we may send a survey later to those willing to respond).

Do you have someone managing fume hoods, inventory, frequency of use, de-commissioning vs de-energizing (shutting down with easy ability to reactivate), etc…

Do you have an inventory of all hoods?

Does anyone manage hood use levels, sash closures, storage of chemicals and waste etc.?

Do you know which hoods are abandoned. No longer usable or needed?    

Do they have occupancy sensors controlling the airflow whether researchers are present or not?

Do you use automatic sash closers?

Have you programmed the hoods into hibernation or decommissioning via the hood’s controller?

Those that reply, may we reach out to you for a deeper dive into these questions and answers?

What specific questions do you have around this topic, that we may be able to answer in our upcoming presentation this fall?

Thank you 

Paul Foote

Think Globally. Act Locally

Energy Efficiency and Conservation Specialist
University of Illinois Urbana-Champaign
F&S Energy Services Retrocommissioning

Email: gfo...@illinois.edu

Office: 217-244-1048

[Allen Doyle]

Hi Paul, 

    Thanks for this enquiry Paul. I'll answer as a former university sustainability manager and now consultant who has reviewed hundreds and hundreds of hoods on about 25 campuses in higher ed, pharma and government labs.  

    Cheers,

	Allen Doyle, MS Safety and Sustainability Specialist “Ensuring Safe & Efficient Airflow Systems for Critical Workspaces”
	Raleigh  Atlanta  Detroit  Hartford  Erie Office 919.319.4290 | Cell 805.729.1581 Web Twitter Facebook LinkedIn

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From: green-lab...@googlegroups.com <green-lab...@googlegroups.com> on behalf of gfoote2 <gfo...@illinois.edu>
Sent: Friday, June 13, 2025 2:42 PM
To: Green Labs Planning <green-lab...@googlegroups.com>
Subject: Fume hoods in higher education

 

Hello Everyone,

I hope you are taking time to enjoy family, good weather and summer fun!
I am preparing for my middle daughters wedding next weekend.  

We would like to know what our peers are doing to help construct the most helpful presentation this fall. 

At this time, we are looking for quick off the cuff answers  for what other universities are doing to manage fume hoods on your campus’. (we may send a survey later to those willing to respond).

Do you have someone managing fume hoods, inventory, frequency of use, de-commissioning vs de-energizing (shutting down with easy ability to reactivate), etc…

    A Rare focus and valuable role. This takes someone with leadership backing who is resilient and energetic (a.k.a. cheerful, decent with arithmetic, and with a thick skin.)  It's important to remember that a fume hood--the metal box with a window—should be an aerodynamic containment device that is the front-facing part of a complex ventilation system. This system continues above the ceiling with valves and sensors that may or may not be accurate, an automation system with low and high setpoints that may have faulty assumptions, long ducts with pressure drops, turbulence, resistance and maybe some leaks, and ultimately to giant fans that may or may not notice if fume hoods are open or closed.  A systems approach is essential to yield the best results for the lifetime of the HVAC system. This "fume hood wrangler" needs to understand this system, and the many technologies and platforms that may control it.

Do you have an inventory of all hoods?  

    Most sites do, and they vary in quality and depth.  From basic to sophisticated:  List of rooms, serial number or campus ID, brand, model, width, last test date, CAV/VAV status, 

    [Bonus search, Very rare: Lists of ducted biosafety cabinets that have exhaust.  Exhaust Rarely needed and may be capped with EH&S and user approval.]

Does anyone manage hood use levels, sash closures, storage of chemicals and waste etc.?

    If BAS has sash position sensor, then that can be "trended." I would say 20% of our client buildings have this.  One has students go through the status regularly and the building manager goes and closes the open ones.  Ideally, sash "diversity" (average percent open) can be under 10%, maybe even 5%.

    Chemical storage records in fume hoods—never seen it.  Amorphous to define, and a nightmare to track.  For example, is a hazardous waste collection site "chemical storage?"  This seems like a professional judgement during an audit or inspection.

Do you know which hoods are abandoned. No longer usable or needed?    

    The decline in use of a fume hood is rarely an intentional process, not apparent to a brief observation, and thus very hard to document. From the 3Flow hibernation report, "...a hibernation recommendation is very tentative as the use history and future of a fume hood may not be obvious.  An active hood that has very good housekeeping may appear empty or in light service, or a rarely used hood may be full of apparatus that has not been moved for many months or longer.  Thus, the observations provided are an opportunity for internal stakeholders to enquire within and compare value, costs, and benefits of hood hibernations."  A user questionnaire or interview that is non-threatening or punitive is essential to find out when other options may be pursued.    

    "abandoned" is a loaded term, so something softer might have better traction.  "Not in use," "In transition," "between jobs" might be preferable. Very difficult to track unless "hibernation" is an actual program with incentives, enrollment, and information. 

    Remember, this is not important in rooms that are not fume hood dominated in their exhaust flow versus "general exhaust".

Do they have occupancy sensors controlling the airflow whether researchers are present or not?

    "Zone presence sensors" are expensive to install and may yield some savings with a) open hoods, and even the b) low flow of closed fume hoods.  These savings can be better achieved through a) sash management to keep sash diversity <10% and b) low flow accumulation testing. 

1. Sash management goals should be to have users close the freaking sash when they don't have their arms in the hood. Close it or go home.  Grrrrrrr... 

    b) While a hood needs to prevent escape of vapors when closed, the primary intent of the low flow setpoint is to dilute a hazardous release of vapors below its lower explosion limit (LEL) and it should not be reduced, whether someone is present or not.  On the other hand, the low flow set point of 375 air changes per hour (really!) has a fudge factor built into it because most fume hoods are untested for their accumulation factor, where vapors may build up in an eddy in the upper portions of the hood.  If the hoods are tested with a tracer release of known amount and measured in several places in the hood when closed and at low flow, that accumulation factor can be calculated and the low flow set point adjusted accordingly.  This is a very technical test, and can yield significant savings in labs with high hood abundance (teaching labs and R&D organic synthesis labs.)

Do you use automatic sash closers?

    We strongly discourage the installation of this "nanny device" as they add a layer of expense and complexity to an already complex system. Simple alarms and professional conduct will achieve the same thing.

Have you programmed the hoods into hibernation or decommissioning via the hood’s controller?    

    This is an essential step with the building automation system (BAS), and it cannot be in isolation without notification of users and prevention of people using a hood when out of service.

Those that reply, may we reach out to you for a deeper dive into these questions and answers?

    Of course.

What specific questions do you have around this topic, that we may be able to answer in our upcoming presentation this fall?

Thank you 

Paul Foote

Think Globally. Act Locally

Energy Efficiency and Conservation Specialist
University of Illinois Urbana-Champaign
F&S Energy Services Retrocommissioning

Email: gfo...@illinois.edu

Office: 217-244-1048

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