A while back, in response to a reader’s question regarding
storage inside the exhaust cabinet, we wrote about the
fundamentals of chemical fume hoods. In that article, we
discussed the basic design principles and operation of chemical
fume hoods. (If your memory is like ours and needs refreshing or
you require another copy, just let us know.) Since exhaust hoods
are among the major expense items for research laboratories and
have a huge impact on continuing operational costs, we’ve
decided to provide you with information on some of the newer
hood designs that offer good performance and energy
conservation. Laboratory exhaust systems fall into three main
classes: chemical fume hoods, for working with corrosive acids
and bases, volatile solvents, and other hazardous chemicals;
biological safety hoods, which can be designed to protect the
work (clean-air bench) or the worker (true biosafety cabinet);
and standard exhaust hoods, typically used in mechanical or
machine shops and their production areas. We are goin