Design Method of Vertical Ventilation with Wind Chimney on Roof Driven by Wind and Buoyancy

The calculation system for vertical ventilation with wind chimney on the roof driven by wind and buoyancy is presented and the necessary data is measured. The calculation system is based on the “pressure – airflow rate relationship (Pressure -Volume curve: P-V curve)” and the local velocity and static pressure at the point of chimney top. The P-V curves were measured by wind tunnel test for some typical shapes of wind chimney top. It is turned out that the effect of upper wind velocity can be eliminated by normalization of the pressure at chimney neck and airflow rate through the chimney. The number of tested models are six : simple outlet, two types of wind-break plates, two types of horizontal duct, rainproof type.