What is the difference between LEV and general ventilation for dust?

General ventilation moves air around the workspace — usually through fans, windows, or HVAC systems. It helps dilute dust levels, but it doesn’t pull dust away from the worker’s breathing zone.

LEV (local exhaust ventilation) is different. It captures dust right at the source — usually with extraction hoods, ducts, and filters placed close to where the dust is generated. Because of this, LEV is much more effective for controlling wood dust exposure.

Think of it like this: general ventilation is “whole room airflow,” while LEV is “targeted dust removal.”