A Study of the Ventilation Performance of a Two-Segment Chimney Integrated with A Residence

A two-segment chimney consisting of an inclined section on the roof and a vertical section near the south wall was studied in a usual two-floor house. Specifically, the effects of the total length and width of the chimney, the inclined angle of the two-layer inlet and the length ratio of the vertical to inclined section on the chimney ventilation performance were numerically studied. The results showed that the ventilation was improved with the increase of the total chimney length. The air mass flow rate increased firstly then decreased with the chimney width, indicating that there existed an optimal length to width ratio, which was 12:1. Similarly, the mass flow rate increased firstly then decreased with the inclined angle of the second floor chimney inlet. The optimal inclined angle was found to be 4°. At the fixed total chimney length, the air mass flow rate also varied with the length ratio of the vertical to inclined section, and the maximum mass flow rate can be achieved by choosing the longest vertical length within the restriction of the building code. These results may provide the theoretical basis for the practical solar building design.