Local Exhaust Ventilation

Brief Overview

Local Exhaust Ventilation (LEV) is widely used to control toxic gases, vapor dusts, fumes and mist from various industrial operations and processes. A proper design of LEV system is necessary for the effective removal of airborne contaminants that would otherwise pollute the work environment resulting in health hazards, nuisance or cause air pollution.

Why it is Needed?

Local Exhaust Ventilation Inspection needs to be conducted to comply to Occupational Safety and Health Regulations. (Use and Standards of Exposure of Chemicals Hazardous to Health Regulations 2000). Every Local Exhaust Ventilations (LEV) system shall be thoroughly inspected and tested upon completion of construction. Periodic inspection is also needed to be conducted throughout the life of the system to ensure continuous performance. The evaluation and inspection of LEV system is to determine the effectiveness of the system and to verify the established or designed operating parameter such as duct velocity, capture velocity and fan speed.

How to conduct?

Local Exhaust Ventilation Inspection is done using measurement meter, smoke tubes, pitot tubes, anemometer and micromanometer. The instruments are used to determine the face velocity, hood static pressure, duct static pressure, hood velocity pressure, transport velocity, air cleaner’s efficiency and fan’s capacity and efficiency. Through the information acquired after detailed observations and inspections, the competent person will provide suitable recommendations to the system.