By James LaFortune and Shawn Postle, Members-at-large for the GCI
The Green Chemistry Initiative (GCI) and the University of Toronto constantly strive to reduce the environmental impact inherent to research in the Chemistry Department. A major contributor to the department’s carbon footprint is its fume hoods, which are required to safely carry out experimentation with volatile solvents or reagents. They provide a partially enclosed working space that draws air from the laboratory into the hood, thereby reducing the researcher’s exposure to chemicals. However, this requires replacing the removed air with acclimatized outside air, a process which consumes large amounts of energy in heating or cooling the air.
Fume hoods are designed with a height-adjustable glass pane (sash) that allows the researcher to work while keeping the space as enclosed as possible. There are two main types of fume hoods used in chemistry labs: constant air volume (CAV) and variable air volume (VAV). With CAV, the air flow remains constant regardless of sash height, while VAV systems are designed to moderate air flow based on the sash height. Each fume hood requires roughly as much energy as three American households when in use. However, roughly 50% of this energy can be conserved in VAV systems if the sash is kept shut. Given that the Chemistry Department has 123 VAV fume hoods, ensuring that VAV sash heights are minimized during idle periods is an effective strategy to reduce unnecessary energy consumption.1
The GCI’s Just Shut It! Campaign, renewed this past summer for its third season since 2008, encourages graduate students to close VAV fume hood sashes during idle times and to minimize sash height when working in the hood. Fume hoods are checked weekly by GCI volunteers to ensure compliance and users of fume hoods found to be in compliance are entered into monthly prize draws. The past two Just Shut It! Campaigns (read more about the original campaign) were very successful, where compliance rates increased from 3% to 61% during the campaign. Since its reinvigoration over the summer, we have recorded similar compliance levels as previous campaigns.
What’s more, the Chemistry Department currently only uses VAV fume hoods in its Davenport wing. However, it is exploring air systems renovations, including replacing CAV with VAV fume hoods in much of the Lash Miller wing. These additional VAV fume hoods will further decrease our environmental impact.
This time around, we are looking to keep the Just Shut It! Campaign going permanently. Gracious thanks to the Department of Chemistry for funding this campaign, especially Chief Administrative Officer Mike Dymarski.
- E. Feder, J. Robinson and S. Wakefield, International Journal of Sustainability in Higher Education, 2012, 13, 338-353.