The design team for a midwestern university’s chemistry building addition decided to use a variablevolume exhaust system throughout the addition. Since the design concepts were unique to the chemistry department’s personnel and the architect/engineers, special efforts were required to ensure a coordinated and acceptable installation. The laboratories use 198 fume hoods in both the teaching and research facilities. The offices and laser laboratories are part of once-through variablevolume supply and exhaust systems. During the 1988 start-up of the facilities, carefully coordinated testing, balancing, and controlling were required to ensure the design criteria were met.