Abstract
Natural ventilation is an important factor in the design of a zero energy building. The design target should be discussed in the early stage of building design because building planning has a considerable influence on successful installation. Against this background, a target air change rate has been proposed for naturally ventilated building designs. In this paper, a map of the target air change rate in Japan is presented. It can be used as design data for architects to determine an effective natural ventilation strategy. It suggests that the air change rate can be set at approximately 4 ACH throughout Japan when the assumed internal gain is general. On the other hand, the target air change rates differ from north to south, and a successful installation can be realized more easily in cool regions than in temperate regions
