Hood Face Velocity -Reply

[Charles Willis <CAW@nrc.gov>]

Chuck,

Hood face velocities of 100 to 125 feet per minute (sometimes linear feet per
minute) are standard requirements but adjustments may be needed for a particular
situation.  These are low velocities, about the speed of a leasurely stroll, so it does
not take much in the way of hand (or other) movement cause stronger counter
currents and move contamination out into the room.  Of course, higher velocities
can perturb the work being done in the hood.  

Just a word of caution --

Charlie Willis
caw@nrc.gov