Describes an analysis by wind-tunnel experiments of the characteristics of cross-ventilation in buildings with open windows. Velocity and pressure distributions inside and outside rooms were measured and analysed in detail. Observes that a kind of stream tube is formed through the building model. Finds that a large part of the dynamic pressure generated at the opening is preserved within the room, and a major part of the preserved energy is directly convected outside the room. The preservation of energy is reflected as a decrease in the value of the total pressure loss coefficient.

KEYWORDS: Wind tunnels, experiment, buildings, windows, ventilation, cross ventilation, pressure, speed.