In a world of vampire appliances, fume hoods are Dracula. These essential fixtures of research labs must run constantly to ventilate work spaces, but in the course of a year a single hood can consume between 1 and 1.5 times the energy used by a residential home.

It was this realization that got Princeton EHS on John Pickering’s radar. Pickering is co-founder of Evidn, a behavioral science firm playing a role in the University’s push to achieve net zero emissions by 2046. He also serves as a non-resident fellow at the Andlinger Center for Energy and the Environment.

Working with the Princeton University Office of Sustainability, Campus Energy and others, Pickering identified three main areas where behavior modification could make a big difference in reaching net zero goals: room scheduling (to minimize electricity and appliance use), student and staff habits around energy consumption, and laboratory practices.

Behavior is Key

Fume hoods are a great place to start because they provide an obvious way to drive energy savings. This makes EHS, with a presence on the ground and relationships with researchers across campus, a key potential partner in change.   

“For Princeton to meet its goals of decarbonizing by 2046, infrastructure and capital projects is the biggest component, but behavior is also big,” Pickering explains. “This is the territory of Joanie.”

That would be Joan Hutzly, Laboratory Safety Specialist at Princeton EHS, who along with Steve Elwood, Associate Director for Laboratory and Research Safety, is working with Pickering to plan and facilitate laboratory programs.

“Hoods are one of the biggest energy wasters,” says Hutzly. “You get people who do not work in front of a fume hood very often, and then they walk away and leave it open, and that whole time all that extra conditioned air is being sucked out.”

All fume hoods feature a sash, which protects the user from vapors and flying debris in the case of an accident, and baffles to direct gases up through ductwork. Fume hoods run constantly, but in most cases flow rates can be reduced by lowering or closing the sash.

Given the scale of energy use, small behavior modifications can drive big savings.

A pilot program running currently at the Rabinowitz Lab in the Lewis Sigler Institute utilizes visual cues: colored triangle stickers which line up when the hood is closed to remind users to leave the sash in the proper position. Signs posted in the labs implore researchers to “Do it For the Hood.”

A web-based dashboard and app developed by computer science students and the Campus Energy & Engineering team in Facilities tracks energy use and makes comparisons to real-word examples such as how many gallons of gas the energy saved is equivalent to.

“A big red alert pops up on the screen of the person monitoring the dashboard if the sash is open more than 5 or 10 minutes,” Hutzly says. “When they see that they know the hood might have been left unattended and they should go close the sash if it is not in use.”

Hutzly and Elwood were consulted to make sure safety was not compromised. “They came to us and said what can we do, what can’t we do?” Hutzly says. “We insisted they cannot cover any baffles or dampers or openings in the back wall of the hood [with stickers or anything else] because that is used for venting.” 

EHS also suggested having labs engage in friendly competition for who can rack up the highest energy savings. With the new tools available to closely measure consumption, this is being considered as a future initiative as the program expands across campus.

The pilot project is already having an impact: the focus on high-consumption fixtures is estimated to save $5000 a year in the Rabinowitz Lab alone, which, along with the qualitative effect of heightened engagement around energy conservation, lays the groundwork for a significant payoff University-wide.

Safety and Efficiency: Perfect Together

For Pickering, safety and energy efficiency are two sides of the same coin. “These things are far from mutually exclusive,” he says, citing lab close-outs, equipment clearance and renovation of laboratory spaces as areas where these goals naturally align.

Thoughtful procurement and maintenance of equipment such as freezers involve hazard mitigation as a component of efficient operations that can create cost savings and lower environmental impact.

“For some time labs were not aware of funds available to upgrade freezers,” says Ijeoma Nwagwu, Assistant Director, Princeton University Office of Sustainability. “Funding was available to support procurement of energy efficient freezers but the initiative just needed to be communicated.”

The ultimate goal, Nwagwu says, is to make sustainability an integral part of lab culture. A focus on fume hoods provides a gateway to sparking awareness of green laboratory practices more generally.

“There is an innate enthusiasm at the labs for conservation practices that can be tapped,” Pickering adds. “Fume hoods are a means of engaging a lab around a purpose.”

Story and photos by Jim Sturdivant