The Invention

The Berkeley Hood: a High-Performance Fume Hood

Lawrence Berkeley National Laboratory has developed a promising new technology, a High-Performance Fume Hood, referred to as the Berkeley Hood in this document. The Berkeley hood reduces airflow requirements by 50 to 70 percent while maintaining, or enhancing, worker safety. Airflow reduction cuts energy costs about $2,100 per year per hood installation, on average.

Berkeley Lab’s hood design uses a "push-pull" approach to contain fumes and exhaust them from the hood. Small supply fans located at the top and bottom of the hood’s sash, or “face,” gently push air into the hood (see Figure 3). These low-velocity airflows create an "air divider" that separates the fume hood’s interior from the exterior (unlike an air curtain approach that uses high-velocity airflow).

Berkeley Lab’s air-divider approach of separating and distributing air (See Fig. 4) leads to greater containment and exhaust efficiency. The result is an extremely effective and energy-efficient unit.

 

Revolutionary Design Delivers Numerousus Benefits

Beyond the 50-70 percent ventilation reduction and associated energy savings, the Berkeley Hood offers design features that deliver a range of benefits, including:

  • Simpler design than the state-of-the-art VAV fume hood systems offers easier and less expensive installations.

  • Constant volume operation ensures that energy efficiency is not dependent on the operator.

  • Clean room-air flowing into the operator’s breathing zone reduces potential hazard from fumes.

  • Supply airflow patterns reduce dangerous eddy currents and vortexes, improving containment and exhaust performance.

In new construction projects, designers will be able to specify the Berkeley Hood and easily achieve energy cost savings.  The Berkeley Hood is expected to have a cost premium over a current standard hood.  However, this cost premium can be offset with savings from installing smaller ducts, fans, and central plants, as well as simpler control systems, Combined, these features yield a lower overall first cost than standard hood systems.

 In retrofit projects, Berkeley Hood users will realize critical benefits beyond energy savings.  Typically, laboratories are “starved” for air as their need for additional hoods has grown.  In some cases, low airflows cause inadequate exhaust and increased potential for hood spillage.  Since increasing airflow is very costly in most cases, many laboratories cannot add new hoods.  By replacing existing hoods with Berkeley Hoods, users can increase the number of hoods or improve exhaust performance.

Based on conservative assumptions, researchers estimate the new Berkeley Hood could save the U.S. over 8,000 GWh/year (assuming 75 percent market penetration).  This amounts to over $1.2 billion in energy savings annually.

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