Inspection Requirements
Local exhaust systems (e.g. elephant trunks, canopy hoods, smog hogs etc.) are often used to remove airborne contaminants. Since their effectiveness is significantly affected by their positioning relative to the source of the contaminants, there are no regulatory standards available to evaluate these systems. As an indication of changes to the effectiveness of a given local exhaust system, one can measure the linear air velocity at the center of their opening over time. A significant drop in linear air velocity is a strong indication that system maintenance is required.
CY 2023 Update
Annual flow rate monitoring of local exhaust systems will be recommended to Facilities Services as a preventive maintenance procedure for CY 2024.