ABSTRACT
Engineers and architects designing laboratories are faced with somewhat divergent demands. On the average, ventilation systems are contributing about 30% of the cost of laboratory buildings and about 80% of their problems. Meet all the safety requirements, e.g., fume hood face velocities and air exchange rates; conserve energy; but build it cheap and minimize upkeep costs. Really redefine what is safe and what is not safe, without using the copout of putting everything in hoods to make it safe. Using whatever faces velocity that is considered safe, one obvious method is to reduce the face opening of the hood. The horizontal sashes also provide a built-in safety shield. That's about it for the "state of the art" hoods. Pouring from one vessel to the other while holding them at or near the hood face will likely get it — in the face.
