Testing a Low Constant Volume Fume Hood—A Viable Green Alternative

Robert Haugen, Kewaunee Scientific Corporation

While comprehensive dynamic tests are not a part of American National Standards Institute ( ANSI)/American Society of Heating, Refrigeration, and Air conditioning Engineers (ASHRAE) 110-1995, it became evident that low-velocity behaviors might go unmeasured unless kinetic challenges were systematically introduced into our evaluation program. The researchers decided to "borrow" kinetic tests rather than design a hood to pass the lone and rather perfunctory dynamic sash movement test already in the ASHRAE 110 standard.

1) The Twister Test: The first "borrowed test" was from Guffey, Flanagan, and van Belle in their American Industrial Hygene Association Journal paper "Air Sampling at the Chest and Ear as Representative of the Breathing Zone 1" and used a rotating mannequin to create a dynamic challenge.

2) EN 14175-3 2 is the containment portion of the European fume hood test standard and it includes a rather intriguing kinetic challenge involving a rectangle 1.9M high by 0.4M deep.

The researchers have taken this procedure and modified it to more closely fit other aspects of the American ANSI/ASHRAE 110-1995:

Using ANSI/ASHRAE 110-1995 and these two additional kinetic tests, the researchers compiled data on the following fume hood challenges:

• Containment during a five minute "static" test (no movement whatsoever).
• Rapid sash movement as described in ANSI/ ASHRAE 110-1995, part 7.12.1. The hood sash was closed, then re-opened within one second three times within a two minute period.
• Four minute "twister".Repeated rotational movement in front of the sash simulating removal or addition of equipment and materials during an experiment.
• An 11 minute "flying rectangle" challenge consisting of 10 complete passing cycles (10 passes right, 10 left). Results reported are max peak height and average mannequin breathing zone concentration.
• Tests 1 and 2 above were repeated with a short stature mannequin of 5'2". (Standard ASHRAE mannequin was 5'8").

All tests above showed very encouraging results.

Biography:

Robert K. Haugen is Director of Containment Control Products at Kewaunee Scientific Corporation. He has served as a leader in the field of fume hood and containment device engineering and design for the past 20 years at Kewaunee, Jamestown Metal Products, and St. Charles Manufacturing. Patents include the LV Fume Hood, dynamic barrier fume hood system, low velocity airfoil, and a pressure-sensing device that allows 3 percent accuracy on face velocity measurement. Haugen has published a dozen articles in the past decade on low constant volume technology.

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