Figure 4-2. Schematic of a local exhaust system.
Figure 4-3. Elements of a local exhaust system.
b. Selection Criteria. Local exhaust ventilation systems are usually specified
when the following conditions exist in the work environment:
(1)
The concentration of contaminant is high.
(2)
The toxicity of the contaminant is high.
(3) The worker's position is close to the point of the contaminant's evolution
(4)
The generation of the contaminant is non-uniform.
MD0165
4-6