ABSTRACT
Major remodeling projects frequently are initiated because older laboratories were built before very serious consideration was given to ventilation requirements. The advent of Occupational Safety and Health Administration, Food and Drug Administration, Resource Conservation and Recovery Act and related federal, state, and local regulations has brought ventilation to the forefront in laboratory upgrading. The fume hood is central to all laboratory design. Jet-type diffusers near the hood face can ruin the performance of the best designed fume hood. Low velocity air introduced at a point remote from the hood face minimizes supply air impact on performance. Wind or lack of air adversely impacts fume hood performance. The number and size of fume hoods may dictate even larger amounts of air. Bench top operations should never be undertaken using toxic materials which should always be used in a hood. All of the air requirements eventually must be accommodated by introducing air throughout the building, customarily by distribution ducts.
