Laboratory fume hoods have long been designed to meet certain face velocity standards. Such standards are committee "consensus" standards, and while not without merit, they lack a foundation of extensive experimental data. This type of standard virtually ignores, except in the most general way, the effect of supply air currents or other disturbances. Furthermore, with the advent of "auxiliary air supplied" hoods, such face velocity criteria become less meaningful and are the subject of much debate.

A performance test is proposed which could be used by the hood designer in developing better designsi and which·could also be used to test hoods as installed and used, thus taking into account all the factors affecting its performance. The test procedure was developed as part of ASHRAE research project RP-70 (1,2).