Airflow in Rooms Dominated by Supply Jets

In rooms where energy is introduced primarily by supply air jets, air distribution methods are referred to as mixing type. With a perfect mixing-type air distribution, airflow pattern and air velocity at any point in the room are 

Current mixing-type air distribution methods typically consider ventilation of the occupied zone with jets intercepting its upper boundary (e.g.. Fig. 7.6l2, c). Also, the occupied zone can be ventilated by the reverse flow produced as the supply jet degrades above the occupied zone level (Fig. 7.6h]. Mixing-type air distribution methods include air supply with jets projected vertically downward, inclined jets, jets directed vertically upward, and horizontal jets along room surfaces. 

FIGURE 7.6 Flow patterns in rooms with horizontal air supply along the ceiling surface (a) primary airflow in a short room (b) primary airflow (c) secondary and tertiary eddies in long rooms.  

CHAPTER 7 PRINCIPLES OF AIR AND CONTAMINANT MOVEMENT INSIDE AND AROUND BUILDINGS 

FIGURE 7.7 Schematics of air supply (o) with inclined jets toward the occupied zone (b) with horizontal jets and occupied zone ventilated by reverse flow (c) with vertical jets. Shaded areas show the effect of buoyant forces on airflow pattern when supply air is excessively heated over the room air  

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