Abstract
In recent years, natural ventilation system is widely used for sustainable buildings. However, systems without proper managements and maintenances are often observed. Noise and pollution are major problems in the urban environment. Wide investigation was conducted for 72 buildings. The reason of less use of natural ventilation system was investigated by the field measurements and questionnaire to the designers, building managers and occupants. The reasons are classified into three categories, 1) complains of occupants, 2) control system of natural ventilation, 3) clear understanding of the natural ventilation system by building managers and occupants. It is found that the actual use time of natural ventilation system tends to decrease and that the designers need to keep contact to the building managers and check whether the system run without problem for long time after it starts to be operated. Sustainable operation was discussed in this paper.
