Buoyancy-induced airflow in a side-heated structure consisting of a cubic box and vertical ducts

Buoyancy-induced airflow in a box with one wall heated, an unheated inlet duct connected to its floor, and an exit duct with one side heated connected to its ceiling is experimentally investigated. A flow rate prediction method based on buoyancy and flow resistance balance is proposed and experimentally validated. The flow pattern and thermal stratification in the box; the flow resistance characteristics for low Reynolds numbers; the relationship among buoyancy, flow resistance, and pressure defect; the chimney effect caused by the exit duct; and the heat transfer characteristics of the heated walls are clarified. The flow rate, thermal stratification, and flow enhancement due to the chimney effect are considerably dependent on the size of the gap of the exit duct.