Variable Air Volume Versus Low Flow Fume Hoods: Design and Economics

Victor Neuman, Precision Environments Group/TAC

The introduction of low-flow fume hood technology is relatively new. The economics of combining these new fume hoods with variable-air-volume (VAV) hood controls still needs to be explained and explored. First cost and operating costs are compared for various designs of VAV hoods, low-flow hoods, sash closers, hood occupancy sensors, and laboratory indoor air quality monitors.

For fume hood dominated laboratories, the low-flow fume hoods offer quick paybacks of one to three years but do not by themselves maximize energy savings.

VAV hood controls offer the maximum in hood energy conservation but usually require longer paybacks than the low-flow fume hoods.

Either hood sash closers or hood occupancy sensors may be needed to obtain energy savings from VAV fume hoods if users cannot be disciplined to close their sashes.

The newest technology being applied is active chemical monitoring in samples taken from the indoor air of the laboratory. This monitoring is then used to drive the air change rates in the laboratory lower when chemical emissions are low.

The design implications as well as first cost impact and sustainability parameters of all these technologies are examined and discussed.

Biography:

Victor Neuman started specializing in laboratory building design at X-nth (formerly Earl Walls Associates) where he was on design teams for 106 laboratory buildings from 1983 to 1990. Later he served as a laboratory mechanical engineer and principal with GPR Planners. Since 1988, he has served as a co-author of ANSI Z9.5 and has received ASHRAE's Distinguished Service Award.

His particular interests include sustainable laboratories, fume hoods, chemical exhaust fans, and laboratory ventilation controls.

Currently, Victor is with Precision Environments Group of Tour Andover Controls. They are a laboratory and cleanroom specialty contractor doing design/build contracts for owners all over North America and the world.

Back to Agenda