You should check with your validation people to determine the system boundaries for your air system and to determine if it is direct impact. They should SOP's to help you determine how to implement the change.
If the tank is inside the direct impact boundary, then you will need to qualify the...
ASHRAE 110 is a Method of Test for Fume Hoods and does not recommend Air Change Rates for Labs.
OSHA regulations call for a minimum of 4 air changes per hour.
Some labs need more than 4 ACH if the Fume Hood requires more air. Work activities may also increase air supply design quantities.
It...
