LEV

Open fronted ventilated enclosures are commonly used in industry to control worker exposure to a wide range of chemicals. These enclosures tend to be of basic design and often consist of nothing more than a box like structure with an open front to allow worker access and extraction at the rear to remove contaminated air. This design forces the worker to stand at the face of the enclosure and by doing so presents a blockage to the airflow.

If inhaled, welding fumes can be harmful to health, thus exposure must be controlled. A commonly used method of control is local exhaust ventilation (LEV) in the form of moveable capturing hoods but, to achieve efficient capture, this type of ventilation must be positioned close to the fume source and moved as welding progresses, although in practice re-location may not always occur. Alternatively, control may be exercised using a low volume high velocity system (LVHV), fitted either to an existing welding torch or manufactured as an integral part of a torch.