Study on the Airflow Structure in Cross-Ventilated Rooms with the Full-Scale Model Experiment

Cross ventilation is one of the most important techniques for maintaining a comfortable indoorenvironment in hot and mild seasons with less cooling energy. But, at present, it is difficult to designindoor environment under cross ventilation because there is insufficient knowledge to evaluate theeffect of cross ventilation quantitatively. Thus the full-scale model experiment has been done in a large wind tunnel to examine the airflow property in the cross-ventilated space. The purpose of this paper is to clarify the airflow structure in the cross-ventilated rooms.Main current region, rebounding and changing direction, deflected flow, surface flow and circulatingflow are confirmed as key factors determining the air flow structure in cross ventilated space. Aircurrent basically goes straight. But after colliding the obstacles, the flow changes the direction, and the deflected flows are formed over and/or under the main current. And when there is enough space beside the main current region, the circulating flow is formed in each room.The room mean velocity is determined by the path of air current. When main current appears clearly,relatively low value of the mean velocity appears in one room. And when main current is divided, theroom with inflow opening has relatively high velocity.