The location of the fume hood in a laboratory is critical to its safe and efficient operation. Fume hoods should not face each other within short distances because air may be drawn from one to provide make-up air for the other.
Laboratory entrance doors, according to Knutson (1987), "can have a detrimental effect on [a hood's] performance... for two reasons. First, the [stream] of air entering the room through the doorway can affect hood performance in the same way as … from a supply air fixture... Secondly, the door [operation] can cause a pumping action. [Knutson, 1987]
