Chapter Flow conditions

When setting up apparatus in fume hoods, care is to be taken that the flow conditions are influenced as little as possible. It must be possible to remove heating baths, other external sources of heat and possibly also cooling baths safely and without changing the apparatus.

This can be achieved, for example, by leaving a clearance of at least 5 cm below the apparatus for the flow of air. Sufficient distances are to be left to the exhaust air openings on the rear wall of the fume hood. An adequate distance (at least 10 cm) also needs to be left to the sash so that the flow conditions are not negatively affected. A fog generator can be used advantageously for the examination of the flow conditions, e.g. a handheld battery operated fog generator (Fig. 11).