What Is an Exhaust System?
An exhaust system is a device that prevents dust, organic solvents, and other substances harmful to the human body generated in the work environment from diffusing into the room by forcibly sucking and exhausting them.
There are three types of exhaust systems: general ventilation systems that ventilate the entire work environment, and push-pull ventilation systems that are installed between two sources of hazardous substances, one for blowing and the other for suction. There are also local exhaust systems that directly suction from a location near the source of the substance.
Especially in work environments where organic solvents are handled, it is mandatory to install an exhaust system and to submit a notification for installation from the viewpoint of ensuring employee safety.
Uses of Exhaust Systems
Exhaust systems are widely used at sites where work involving the handling of organic solvents and dust mainly occurs.
General exhaust systems are easy to use because of their superiority in terms of workability and installation cost. They are not suitable for handling high-risk organic solvents and other materials because of their low ventilation effectiveness and the difficulty of handling exhaust air.
On the other hand, local exhaust systems and push-pull ventilation require large equipment, but they can selectively collect and treat exhaust air, preventing high-risk substances from diffusing into the environment.
Principle of an Exhaust System
The main overall ventilation system used in exhaust systems is ventilation fans. Multiple ventilation fans are installed in a work environment to circulate air and dilute hazardous substances to maintain a safe working environment.
Local exhaust systems and push-pull ventilation systems, on the other hand, are designed to create a more active airflow and collect hazardous substances.
Local exhaust systems either cover the source of the hazardous substance with a hood for suction or install a hood directly next to the source for suction at high exhaust airflow rates to prevent the substance from spreading into the environment. The most effective type is an enclosed hood. However, open hoods are also used depending on the work environment and substances to be handled.
Push-pull ventilation systems are designed to prevent exposure to high concentrations of hazardous substances by creating a uniform flow of air in a particular work environment and can exhaust a wider area than local exhaust systems.
It is important that the performance of local exhaust systems and push-pull ventilators be maintained, so guidelines for voluntary inspections have been established for the handling of organic solvents.