Enhancement of cross-ventilation of a detached house using roof surfaces in densely populated urban areas Part1 Wind pressure distribution by wind tunnel experiment

In Asian countries under sultry climatic conditions includingJapan, natural ventilation and cross-ventilation at nighttime give very good effects on the improvement of physical conditions of the residents and on the coolingof the buildings in intermediate and summer seasons.However, a densely populated urban area such as Tokyo, sufficient ventilation flow rate may not be necessarily maintained because the distances between neighboring houses are shorter and also because of the problem to keep privacy of the residents between the windows, which are positioned face-to-face on wall surfaces. In Part 1 of the present study, it is attempted to perform wind tunnel experiment to evaluate the changes of wind pressure coefficient on the buildings when gross building coverage ratio is changed, and assessment is made on the possibility to effectively utilize the results of the study of cross-ventilation on roof surfaces in the densely populated urban area. The results of the study suggest that, in case the openings are installed on roofs, better effects can be expected on roof surfaces than the case where the openings are installed on wall surfaces.