Since exposed duct systems generally result in lower construction costs, there has been a surge in the use of exposed-type terminal outlets. Fortunately, there are several types of terminal outlets that allow different methods of airflow distribution. Most commercial and industrial air distribution applications require one of the following types of methods: localized or concentrated distribution, air dumping (displacement ventilation), or a combination of the two, which we will call "localized air dumping." Figure 1 shows the airflow patterns of each type of terminal outlet discussed. The terminal outlet chosen should match the airflow distribution requirement.
We will examine some of the features of several types of terminal outlets that use the three methods of air distribution discussed.