Local Exhaust Ventilation (LEV)

About this category

This class serves capturing contaminants at their source to reduce their release into the surrounding work area. An LEV system is integrated and comprises elements that vary by system design and may include a capture inlet or local-extraction hood at the source, ducting, an air-moving device (such as a fan or blower operating in extraction mode), filtration or collection equipment, discharge arrangements, and operating controls. System capacity, filter type, noise level, and power requirements vary by model and application. Technical note: the air-moving device is a component within the LEV system, not a substitute for it; a blower by itself is not LEV. Potential accessories by model: filters dedicated to the contaminant type, performance-monitoring systems, filter-blockage alerts, and control valves. Uses: welding and cutting shops, chemistry laboratories, pharmaceutical manufacturing facilities, industrial printing facilities, paint facilities, and food-processing facilities. Operating considerations: selecting the system based on contaminant type and generation point, installing the capture inlet near the generation point, periodic filter inspection and replacement, and integration with the general ventilation system. A substantive difference from general ventilation: LEV is intended to capture the contaminant at source, while general ventilation is intended to dilute contaminants after spread; actual outcomes vary by system design and installation. Model specifications, system design, filter type, and installation requirements are reviewed in the product documentation.