What type of system is an adjustable 'elephant trunk'?

An adjustable 'elephant trunk' is classified as a local exhaust system. This type of system is designed to capture and remove airborne contaminants from a specific source at the point of generation. Local exhaust systems are highly effective in controlling exposure to hazardous fumes, vapors, and dust that can occur during welding and other metalworking processes.

The 'elephant trunk' itself refers to a flexible, movable duct that can be positioned to direct the extraction of contaminants directly from the source where they are produced, ensuring that the worker is protected from inhaling harmful substances. This system focuses on minimizing the pollutants at the source before they can disperse into the larger workspace.

Other ventilation options may not provide the same level of targeted extraction. While natural ventilation systems rely on air movement that occurs without mechanical assistance, and mechanical ventilation systems involve the use of fans to circulate air throughout a space, they may not achieve the localized extraction needed to manage specific pollutants effectively. Positive pressure systems introduce clean air into a workspace, but they do not remove contaminants, making them less suited for controlling welding fume exposure. Thus, a local exhaust system like the adjustable 'elephant trunk' is the most appropriate choice for effective fume extraction in welding operations.