Diversity in laboratory exhaust systems can theoretically be used to downsize equipment and reduce capital and operating costs. Provides a method for analysing and reporting laboratory diversity data and applies this method to three facilities. Results indicate that substantial diversity exists in real operating facilities provided three key motivators are effectively in place. These motivators are (1) facility design and function, (2) training, and (3) monitoring and enforcement. It is suggested that the fume-hood-to-personnel ratio may predict the facility diversity provided that these motivators exist. Because of the small sample size reported on, more research is indicated to determine the accuracy of this ratio in predicting laboratory exhaust diversity.

KEYWORDS: measuring, calculating, laboratories, case studies, exhaust hoods, ventilation, variable volume air conditioning, accuracy.