Natural ventilation of buildings using ambient air movement is an economic option for enhancing room air circulation and reducing mechanical forcing costs. FLUENT software can be used to simulate natural ventilation and assess it usefulness. One test involves filling a room with a tracer gas, and tracking the decay of the tracer as a result of an oncoming outside breeze. FLUENT results are in excellent agreement with data for this case (Ref. 1).

Contours of tracer concentration on a horizontal slice through the room. After a short period of time, the tracer is being blown from the room by an oncoming breeze through an open window.

Reference 1: "Model scale and numerical evaluation of tracer gas distribution due to wind forced natural ventilation", J. B. Birdsall and R. N. Meroney, Ninth international conference of wind engineering, New Delhi, India, Wiley Eastern Ltd., pp. 1693-1703.