The effectiveness of displacement ventilation.

The effectiveness of ventilation related to the two primary tasks of ventilation, (I) the supply of fresh air, and (ii) removal of contaminants, is investigated. To allow a quantitative description of ventilation performance, several effectiveness numbers are discussed, and their dependence on air flow characteristics is explained. The effectiveness of displacement ventilation regarding renewal of the internal air population is analysed both experimentally and by means of Computation Fluid Dynamics simulations.