By Hilary Smith, Sustainability Resource Center
When it comes to making research more sustainable, sometimes what it boils down to is just a lot of hot air. A pilot behavior change initiative in the Sorenson Molecular Biotechnology Building, initiated by Facilities Management, reduced wasted airflow and trimmed heating and cooling costs by encouraging researchers to “Shut the Sash” on fume hoods when the devices are not in use.
Because of the success of the pilot program, the Shut the Sash campaign will be launched campus wide over the next year.
A fume hood is a crucial piece of equipment in any working lab. It’s a device that ventilates a work area so the researcher does not inhale dangerous fumes, vapors, or dusts. Inside a hood, fans move potentially contaminated air outside the building then move exterior air back into its place.
To safely remove all potentially hazardous fumes, a hood must move a large volume of air. U of U Facility Manager Joe Ashurst says that when the sash on the front of the hood—a sliding glass panel—is open, fans move about 1,000 cubic feet of air per minute outside of the lab building. Flow is significantly less, about 250 cubic feet per minute, when the sash is closed. Ashurst notes that some air flow must be maintained at all times because traces of chemicals used inside the hood might otherwise waft out into the lab, so the sash is not designed to provide a perfect seal. Environmental Health and Safety staff members periodically check the hoods to ensure that the air flow, or “face velocity,” never dips below a set level in order to minimize the risk of a dangerous chemical escape, says Ashurst.
After the potentially contaminated air is removed, fresh air from outside is moved in to replace it. This new fresh air is heated or cooled, depending on the season. Over time, all that air and heating and cooling energy adds up. According to a 2006 paper by researchers at UC Berkeley, over the course of a year, an average fume hood consumes 3.5 times the energy consumed by an average household.
Across campus, there are around 1,000 fume hoods whose air flow can be limited by shutting the sash.
The devices’ high energy needs became apparent to Ashurst when he read an article about what other universities were doing to reduce their labs’ energy consumption. A Facilities Management team got together in the summer of 2014 to explore the issue.
Ashurst says an informal inspection showed that almost half of the sashes on the 75 fume hoods in the Sorenson Molecular Biotechnology Building were at least halfway open, even while the hoods were not in use. Subsequent observation confirmed tendencies to leave the sashes open. Ashurst says it’s an easy mistake to make—a working hood does not make a loud noise, and the difference in sound between an open-sash and a closed-sash hood is slight.
Closing sashes and reducing air flow saves cost and energy in three ways, explains Ashurst: by reducing the electricity needed to power the fans, by making air filters last longer, and by reducing the energy used to heat or cool the fresh air that replaces the removed air.
Ideas were bandied about for a campaign to encourage lab users to “Shut the Sash.” Stephanie Dolmat-Connell, sustainability manager for Facilities Management, says several elements of the U of U’s campaign were based on successful campaigns at other universities, including Harvard and UC Davis and Santa Barbara. Funding came from the Energy Management Office within Facilities Management. The most visual elements of the campaign included stickers (designed in-house and placed on hood sashes, reminding users to “Shut the Sash”) and poster and digital displays in elevator lobbies placed next to six different lab areas within the building. Posters listed each lab area’s air flow targets, while the displays show actual, real-time total air flow for all the hoods within each lab.
“Our placement gives instant feedback when people are leaving the lab to show how the lab is doing—if someone is the last person out, it may remind them to go back in and shut the hoods,” says Dolmat-Connell.
The campaign also included a kickoff meeting with the principal investigators in the building and the vice president of research in order to bring them on board, as well as an informational event in the building’s main lobby, where members of the campaign team passed out cookies and explained what the displays mean.
Ashurst says the project team observed a much greater effort to keep sashes closed when not in use after the campaign began. Informal surveys of the building’s labs were performed both before and after the campaign began; before, only 46 percent of the hoods’ sashes were “mostly closed,” and after, 64 percent were “mostly closed,” says Dolmat-Connell. Since the project started, the building has seen an average reduction in cubic feet per minute of air flow of about 5.8 percent, she says.
“Prior to the campaign, people did not understand the implications on building energy consumption and the connection to closing the hood,” says Ashurst. “It wasn’t so much that they were forgetting; it was that they didn’t understand that it was the right thing to do.”
Hilary Smith is a graduate student in Environmental Humanities. She is a graduate assistant with the Sustainability Resource Center.