Air distribution in mechanical ventilation system

The air distribution in spaces is a major important factor for occupants' health, comfort and performance as well as for efficient energy use. In many buildings, mechanical systems are used to transport and supply clean and cooled/heated air to occupied spaces. Air distribution in such ventilated spaces in general depends on inertia and buoyancy forces, initial conditions of the supplied flow and boundary conditions in the space. Different air distribution strategies based on the mechanical systems for air transportation are used to achieve the goal of thermal comfort and air quality. One of the strategies is to mix the supplied clean air and cool/warm air with the polluted air in the space. Dilution of the supplied air with room air is the aim of mixing ventilation. Another common strategy is displacement ventilation, where a stratified flow is created using the buoyance forces of heat sources. The air quality is then generally better than with mixing ventilation.