A review: Natural ventilation performance of office buildings in Japan

Natural ventilation is an effective strategy for reducing energy use in buildings. The effect is especially significant for buildings with high internal heat generation, such as commercial office buildings. Therefore, naturally ventilated office buildings are becoming increasingly popular in Japan. In this paper, monitoring and measurement results from Japanese studies are reviewed. Thirty buildings are selected for the review based on the search results obtained using a Japanese search engine for academic papers. To identify trends in the design of naturally ventilated buildings, the representative air change rates are compared. The values range from 1 to 10 ac/h, and no specific peak is observed. In addition, no strong correlation is found between the air change rates and floor areas. These results suggest that the natural ventilation performance depends considerably on the design. Additionally, the natural ventilation performance is highly dependent on the building shape, which is generally discussed during the early stages of building design. In this context, it is important to create a clear target air change rate within the range of achievable values for natural ventilation design in the early design stage and to consider this target throughout the building design process.