Walk-In Fume Hoods
Walk-In Fume Hoods: Laboratory Design for Large Equipment
If your laboratory requires fume hoods that house large equipment, walk-in fume hoods are an excellent option.
While the name might indicate otherwise, walk-in fume hoods do not allow users to walk in and out of the fume hood while it is being used. Walk-in fume hoods, which are basically bench hoods that reach the floor, do allow users to walk in and out to set up equipment before and after work begins.
Walk-In Fume Hood Design
One of the first things to consider is floor design. Because the floor and the hood entrance are basically at the same level, issues associated with air flow at floor level—specifically walking, deflected currents, and air leakage under doors—must be taken into consideration. The best way to combat these issues is to adjust the back baffle slats. Setting the top baffle to an opening of one inch and opening the bottom baffle all the way will ensure good floor sweep.
When it comes to sashes, walk-in fume hoods can have either double-hung vertical rising panels or horizontal sliding panels. While both are acceptable, horizontal sashes tend to move more easily. Since walk-in fume hoods are not as vulnerable to room air currents when the sashes are closed, many find horizontal panels the better choice.
Depending upon the application of your fume hood, other design factors may include floor drains and physical barrier controls. Depending upon the materials being used in the fume hood, manipulations to one or both of these elements may be necessary to prevent harmful contaminants from entering the laboratory or the environment.