What height should the inlet to an exhaust system be located regarding contaminant concentration?

The correct choice is centered on the principle of minimizing the exposure to harmful gases and fumes within the environment. The inlet of an exhaust system should be located in a position where it can capture the heaviest concentration of contaminants. This ensures that the most polluted air is effectively removed from the workspace or building, therefore enhancing the quality of indoor air.

When exhaust inlets are situated at points with higher contaminant concentrations, they can more efficiently extract pollutants before they disperse throughout the area. This is especially critical in environments where hazardous substances may accumulate, as it helps ensure a safer work environment for individuals.

Although the clean air zone may seem like a logical choice, it would be less effective for ensuring that contaminants are actively removed from the environment. Placing an inlet in a clean air zone would not address or mitigate the presence of contaminants adequately, leading to potential health risks and compromised air quality. The focus on capturing the heaviest concentration of contaminants allows for better overall ventilation and air purification, which is essential for maintaining safe conditions.