Measurement of natural ventilation rate in Japanese residential building

It is difficult to design indoor environment under natural ventilation because there is insufficient knowledge to evaluate the effect of the natural ventilation space quantitatively.Especially, natural ventilation rate is not yet fully understood.In this paper, the properties of the naturalventilation with large openings are examined mainlyfrom the measurement result of ventilation rate. As a result of the measurement, the resistance of the interior doors is large and the ventilation rate is almost caused by air exchange in one opening when the interior doors are closed (single-sided ventilation). In contrast, high ventilationrate is caused when the interior doors are opened (cross ventilation). And it is confirmed that what factors influence the ventilation rate through the large openings.