ABSTRACT
The ventilation rate in the cavity of a double facade is dependent on the characteristic of the wind directly in front of the facade. This effect was investigated by wind tunnel tests. The results show, that the turbulence and the integral length scale are not sufficient, to describe the amount of the air change. The frequency resp. the wavelength of the wind speed in the opening has a strong influence on the ventilation rate. Only a high quota in the wind spectrum that matches the dimensions of the openings leads to high ventilation rates.
