Displacement ventilation (DV) is an air distribution system designed to simultaneiously improve indoor air quality and reduce energy use. Cool, rather than cold supply air is provided through low sidewall diffusers directly to occupants. The cool air, at about 65 degrees F rather than 55 degrees F, falls to the floor due to gravity and spreads across the floor. When the cool supply air comes into contact with occupants and equipment, the heat from these sources causes the air to warm and rise. This creates a vertical air movement, driving heat towards the ceiling exhaust. Room contaminants are carried away towards the ceiling exhaust, resulting in improved air quality near the occupants. Schools, restaurants, theaters and auditoriums, atria, other open spaces with high celings, and places where air quality is a concern are excellent applications.

This case study describes a DV demonstration comparing two classrooms, side by side at Kinoshita Elementary in San Juan Capistrano, California.