The average fume hood consumes three-and-a-half-times as much energy as an average house in the U.S. Fume hoods are widely used to protect workers from breathing harmful substances in research laboratories, industrial shops, school labs and pharmaceutical and biotechnology facilities. A typical hood is a box, often mounted at tabletop level, with a moveable window-like "face" or sash. Hazardous fumes are drawn out of the hood through a port at the top. Researchers at Berkeley Lab estimate that the one-half to one million fume hoods in the U.S. cost $4.2 billion in energy bills to operate each year, corresponding to 26 terawatt hours of electricity, 193 trillion BTUs of heating.1 Berkeley Lab's new "Berkeley Hood" protects workers with a "curtain of air," demands about one-quarter as much of energy as traditional fume hoods, and is actually more effective at containing hazardous fumes.
In 1997, Berkeley Lab scientist Dr. Helmut Feustel built the first prototype of the "Berkeley Hood" out of cardboard, duct tape, and plastic piping. Feustel, who was trained as an airflow engineer, used both displacement airflow principles and methods used in hospital operating rooms to keep wounds clean to develop his revolutionary design. He demonstrated that his invention was effective, and the California Institute for Energy Efficiency (CIEE, now called California Institute for Energy and Environment) and a variety of other public-goods organizations began funding further research on the promising new technology. Geoffrey Bell led the effort to refine and bring the technology to market, and in 1998 Berkeley Lab filed for the first patent for the Berkeley Hood.
The Berkeley Hood reduces airflow requirements by 50 to 70 percent, resulting in substantial energy savings in excess of 70 percent. Another advantage of the Berkeley Hood is it that it reduces dangerous eddy currents and vortexes. A patented "air divider" technique, similar to a "push-pull" ventilation system, optimizes supply airflow patterns. This improves containment and reduces the potential for hazardous fumes in the operator's breathing zone.2 The simple application of the Berkeley Hood offers easier and more cost-effective installations than other state-of-the-art fume hoods.
Normally, air entering the hood is required to have a minimum airspeed or "face velocity." The Berkeley Hood, however, keeps pollutants from spilling out using a lower face velocity than traditional fume hoods. The American Society of Heating, Refrigerating and Air-Conditioning (ASHRAE) Standard 110-1995 includes a more robust test method than standard face-velocity measurements: it requires releasing a tracer gas inside the fume hood and testing how much reaches the breathing zone of a mannequin. In 1998, the Berkeley Hood passed the containment thresholds recommended by the American National Standards Institute, then, and currently per ANSI Z9.5-2003, for the ASHRAE 110-1995 test method, proving that it contains hazardous fumes as well or better than conventional hoods, with a fraction of the airflow and energy use.
Initial test sites for the Berkeley Hood in the year 2000 took place at Montana State University (MSU) and the University of California, San Francisco Medical Center, funded by PG&E. Scott Rogers, the Chemical Safety Officer/Hazardous Material Manager for MSU wrote of the Berkeley hood, "The low-flow hood has shown a better than adequate ability to contain and remove odors, vapors, and aerosols from the hood area. Smoke tests at flows well below a face velocity of 100 fpm [feet per minute] show excellent containment... The low-flow hood has shown to be easy to use and very effective." Further testing of the Berkeley Hood at San Diego State University, funded by SDG&E, was similarly successful, and the hood has performed well during advanced challenges including Human-as-Mannequin testing.3 The California Energy Commission (CEC) has also funded extensive testing analysis of the Berkeley Hood.
In 2002, thanks to Bell's work, Berkeley Lab received a second patent for the Berkeley Hood, which specified geometric arrangements of the design.
Nationally, there is a lot of interest in the Berkeley Hood, but it cannot be used in California without a variance from Cal/OSHA requirements. It does not pass the Cal/OSHA standard which makes California the only state to require fume hoods to have an average face velocity of at least 100 feet per minute.
Recently, Berkeley Lab granted an exclusive license to the ESCO Corporation, a group of companies that create products for industrial application, for the manufacture and market of the Berkeley Hood, renamed the Frontier® Guard Fume Hood. Berkeley Lab researchers estimate that potential American electricity savings for the Berkeley Hood are $1.6 billion annually.4 The creation of the Berkeley Hood has inspired the development and commercialization of a number of other high-performance hoods in the industry, as well as heightening awareness of the importance of fume-hood energy use.
- Esco (Laboratory Fume Hoods Division)
- Berkeley Fume Hood project website
- Available for licensing: Energy Efficient Laboratory Fume Hood
- "Energy-Efficient Berkeley Fume Hood Cuts Energy Use in Half"
- "Advanced Fume Hood Capable of Immense Savings in Energy Costs"
1 Mills, E. and D. Sartor. "Energy Use and Savings Potential for Laboratory Fume Hoods." Energy, Vol. 30, 2005, pp. 1859-1864. LBNL-55400.
3 Bell, G. and D. Sartor. Side-by-side Fume Hood Testing: Human-as-Mannequin Report. LBID-2561, October 2004.