Green Intentions September - Shut That Sash! by Özlem Bulut

Many of us lab people probably have spent hours sitting in front of a cell culture cabinet (why I need a back massage most days) or a chemical fume hood. We need them to protect both the research and the researcher. But did you know that fume hoods are one of the most energy-consuming parts of lab equipment? Even more than the one we have already been talking about, ultralow temperature freezers.

Fume hoods need to constantly circulate massive volumes of air, which costs a lot of energy. Because of the turnover, the air outside the cabin needs to get heated or cooled constantly as well. Energy costs for a typical hood range between $4,600 and $9,300 per year, depending on the climate conditions. Unfortunately,  their sashes are too frequently left open even while no one is working there. However, the simple act of closing the sash when the equipment is not in use, or even lowering the sash a little bit, makes a big difference in carbon footprint and the energy bill.

By shutting the sashes of just two hoods, a University of Maryland lab reduced their annual CO₂ emission by 41,756 pounds (around 19 metric tons), which is more than the annual emissions of two average households. With their Shut the Sash challenge that involved 150 fume hoods, Harvard’s Chemistry and Chemical Biology department saves $180,000 and 300 metric tons of CO₂ emission every year.

A similar program implemented at MIT’s Chemistry Department saved them $41,500 a year and prevented 160 tons of CO₂ emissions. In this case, the average sash height was lowered only by 26 percent. They estimate to at least double the saving if the sashes were shut completely.

In another approach by the University of Nottingham, a variable volume extract system was installed to adjust the airflow rate according to sash height. This could achieve a 25% less air extract rate when the sash was in the lowest position. In addition to that, sensors were installed to automatically close the sash when the cabinet was not being used. The project cost £81,500, but they expect to save 130 tons of CO₂ and £19,300 per year.

With a bit of research, you can find many more examples like these. With effortless changes, tangible progress is possible. Biosafety cabinets, like the ones in cell culture, are not as crazily energy-consuming as fume hoods, and they are less extensively studied in sustainability efforts. However, we can still make a habit of closing their sash or shutting down the flow, depending on the equipment. My lab alone has 7 of them, so all the labs together would amount to meaningful savings for our institution’s carbon footprint.

Maybe you might hear about a fume hood challenge in the near future, just like the Radboudumc Freezer Challenge. Or maybe you don’t need an official challenge to start making efforts. For September or hopefully longer than that, join us and shut that sash!

The Green Lab Initiative is a new collaboration of green enthusiasts at the Radboudumc who want to encourage people to go greener in the lab. With our green intentions of 2021, we try to inspire you every month to take small steps. Find us on Twitter or LinkedIn!

Blog by Özlem Bulut