This creates a stratified flow where the cooled supply air flows out into the room under the warmer room air.

The flow in the room is based on natural air movements where the air is driven by a difference in density and by convection flows from heat-releasing activities and processes.

Convection flows at heat sources generate a vertical air flow in the room, thereby creating a clean zone on the bottom and a polluted zone on top.

A high level of heat activity from heat sources generates bigger convection flows, resulting in the air rising more strongly and greater entrainment of the air around the source.