Regional classification maps for engineered natural ventilation design of office buildings in Japan

Abstract

Natural ventilation is an essential component of green building design. Thoughtful consideration of natural ventilation in the early stages of building design is important for its successful integration. In this paper, we suggest the utilization of regional classification maps. Two maps are presented: a map of target air change rates for natural ventilation and a map of the total hours in which natural ventilation can be used throughout the year. The target air change rate is defined as the point at which the slope of the increase in the cooling effect due to natural ventilation reaches a maximum, and the proposed maps show the distributions of the target air change rate in Japan. The total natural ventilation hours are determined by calculating the period during which the outdoor air is usable for natural ventilation. The maps were created based on 836 points of weather data from Japan. These maps can help architects and building engineers understand the effects expected from natural ventilation system integration during the process of decision making in the early stages of building design.