Building simulation on utilization of roof window in detached house by using cross-ventilation

The effects of roof window on ventilation flow rates and reduction of cooling loads in densely populated areas were investigated by using building simulations. In May of the intermediate season, when utilizing roof window, the cumulative number of air exchanges increased by 9 % to 12 % compared to that when the windows at side walls remained open only during the daytime. When the building coverage ratio increased from 0 % to 20 %, the cumulative number of air exchanges decreased and the cumulative cooling loads increased. However, when the building coverage ratio increased from 20 % to 40 %, the cumulative number of air exchanges and cooling loads remained almost the same.