Adequate Face Velocity for Laboratory Hoods

Multiple organizations have adopted laboratory hood safety standards to determine the effectiveness of a hood in limiting occupational exposure. One such measure of determining the effectiveness of the hood is by measuring the speed of air entering the hood (i.e. the face velocity). While face velocity is not the only test method […]

Ask the Expert: Ventilation and Fan Requirements

D. Jeff Burton, PE, CIH, noted author and OH&S contributor, lends a hand on this “Ask the Expert” question.

Q: How do I go about taking measurements for an old, underperforming laboratory fan for specification of a new fan?

A: When specifying a fan, the two basic numbers you need are Q and SP — […]