Chemical fume hoods are the largest energy "hogs" in typical research and teaching laboratories. Chemical fume hoods consume energy in two ways: to power their fan system and by ventilating high volumes of conditioned air. Laboratories are required to have air that is 100% outside (fresh) air; no air is recirculated. Thus, a chemical fume hood "sucks" out this conditioned air at a high volume. While these measures protect lab occupants from exposure (which is important), it also consumes enormous amounts of energy. Closing the sashes when the hoods aren't being used is the most effective way to balance the safety needs while reducing energy consumption. Closing chemical fume hoods when not in use can reduce energy by up to 60% at that hood1. When you consider that Vanderbilt has over 800 fume hoods, shutting the sash and turning off blowers when the hood is not in use can make a big difference! Other fume hood facts to consider:
A University of Michigan study found that chemical fume hoods are used an average of 2.6 hours during an average workday2. That is only 10% of each day. Closing the Sash could save over 50% of the energy used by that fume hood.
The energy that “escapes” from a chemical fume hood (in the form of conditioned air) over the course of a year is enough energy to power more than three residences for an entire year1.
University of California – Berkeley reduced energy use in one of their research buildings by over 5% just by closing chemical fume hoods, creating a savings of 19,000 kilowatt-hours over the course of a year3. That’s enough energy to power the average residence in Nashville for almost 15 months4.
Educating research faculty and staff on chemical fume hood energy conservation has been shown to be effective. Duke University saw a measurable decrease in the amount of air being exhausted from laboratories immediately following the roll-out of their training program on fume hood sash management5.
...a research building consumes 5 to 10 times more energy than an office building6 ?
1 Emig, Jaclyn, Harvard University. “’Shut the Sash’ Behavior Change Programs in Labs at Harvard”, Labs21 Conference, October 2006.
2 Newman, Victor (P.E.), Precision Environments Group. “’VAV and Low Flow”, Labs21 Conference, October 2007.
3 University of California – Berkeley Green Campus Program, “Shut the Sash Saves Net $21,000”, 07/07/08.
4 Nashville Electric Service web page “Residential Rates”, 2008 .
5 U.S. Environmental Protection Agency, Labs21 Program, “Metrics and Benchmarks for Energy Efficiency in Laboratories”, October 2007.
6 U.S. Environmental Protection Agency, Labs21 Program, “An Introduction to Low Energy Design”, August 2000.