Where should exhaust systems be placed for effectiveness?

Exhaust systems are most effective when they are positioned no more than 12 inches above the floor. This placement allows them to capture and remove harmful gases, dust, fumes, or vapors that are generated during construction activities at their source. Many hazardous substances are heavier than air and can settle close to the ground; therefore, having the exhaust system positioned at a lower height ensures that these contaminants are effectively drawn into the system before they can disperse throughout the workspace.

Positioning the exhaust system too high or too far from the floor could allow pollutants to accumulate in the work area, increasing exposure risks for workers. Additionally, the height of 12 inches accommodates a balance between effectiveness in removing harmful airborne substances and maintaining unobstructed workflow at ground level, which is critical in construction environments.