A ventilation system can be defined as any process that supplies or removes air, by natural or mechanical means, into or from an area. Since the air in an industrial setting may become contaminated or heated.
Industrial ventilation systems are designed to keep the air breathable and thermally comfortable as it is being supplied or removed. Although air moving systems come in many shapes, sizes and forms, industrial ventilation systems are commonly composed of hoods, ducts for transporting contaminated air, filters, fans, and a point of exhaust.
By capturing and controlling contaminants near their source or by diluting them with large quantities of fresh air, air-moving systems reduce airborne contaminant once nitration without requiring individuals to wear respirators.
Types of Ventilation Systems
There are two broad classifications of air moving systems: local exhaust ventilation and General (or dilution) ventilation.
Local exhaust ventilation systems capture and remove contaminants at the point of a generation before they can escape into the workroom air. This type of ventilation system is one of the most widely used engineering control technique. By design, local exhaust systems are well suited for processes which generate large amounts of dust, use harmful or flammable chemicals, or would otherwise present housekeeping or employee comfort control problems.
General ventilation systems are designed to supply areas with large amounts of fresh air to keep the concentration of contaminants within an area below the recommended exposure limits. For example, carbon monoxide gas may be produced when propane gas-powered vehicles are used indoors. In high concentrations, carbon monoxide may cause headaches and nausea. Obviously, mobile vehicles cannot be locally exhausted. Therefore, facilities using propane vehicles must provide sufficient fresh air exchanges to control carbon monoxide concentrations. Since contaminants are not removed from the atmosphere before entering an individual’s breathing zone, general ventilation is not recommended for the control of extremely toxic chemicals. General ventilation systems, therefore are used in areas where small amounts of chemicals are used.
