ABSTRACT
Ventilation is required for every human occupancy and is routinely used to provide thermal comfort and to control airborne contaminants. The three major categories of ventilation used for airborne contaminant control include (1) general or dilution ventilation, (2) displacement ventilation, and (3) local source or local exhaust ventilation. (Terms, units, and definitions are found at the end of the chapter.)
Natural dilution ventilation (air movement induced by wind and temperature differences) has been used for centuries to control smoke from fireplaces, stoves, and tobacco products. Mechanical dilution ventilation has been used widely since the 1890s to control indoor air contaminants including environmental tobacco smoke (ETS).
