Fume hood performance: Face velocity variability inconsistent air volume systems
- Rockefeller Univ., New York, NY (United States)
- Lab. Safety Services Inc., Butler, NJ (United States)
A 3-year survey of 366 bench-type fume hoods in working laboratories in conventional, constant air volume settings showed that face velocities varied greatly from unit to unit and over time. Fume hoods with bypasses performed better than those without; however, even newly fabricated bypass hoods exhibited large variations. These variations were due to several factors; however, face velocities at 100 {+-} 10 ft/min at working sash heights in the range of 20 to 40 cm (8 to 16 inches) were attainable. The use of smoke showed poor containment, especially at face velocities below 85 ft/min (0.425 m/s) or above 130 ft/min (0.65 m/s) and when the hoods were obstructed by large items placed on the work surface. Auxiliary/supplemental air created unstable face velocities and poor smoke patterns. The analysis of 3 years of fume hood monitoring showed clearly the need for and importance of a maintenance program where the fume hood lower slots are cleaned and fans, ducts, dampers, and hoods are checked periodically.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 290247
- Journal Information:
- Applied Occupational and Environmental Hygiene, Journal Name: Applied Occupational and Environmental Hygiene Journal Issue: 9 Vol. 13; ISSN AOEHE9; ISSN 1047-322X
- Country of Publication:
- United States
- Language:
- English
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