The Research Of Window’s Discharge Coefficient In The Natural Ventilation Room

In recent years, in many measures of reducing buildings energy consumption, naturalventilation has attracted more and more people’s attention. Reasonable use of naturalventilation not only reducing the buildings energy consumption, but also can provide freshair and improve the indoor thermal environment and air quality. Windows connectedbuilding inside and outside, its resistance properties directly affect effect of building naturalventilation. At present, the domestic and foreign researchers has achieved greatachievements in theory research of buildings natural ventilation, but study of window’sdischarge coefficient remains to be further. Therefore, this article take discharge coefficientof window as the research subject, analysis and research the size of window’s dischargecoefficient and main influence factors, to provide help for effective use of buildings naturalventilation.This article applies theory of model experiment, designed and construct experimentalwind tunnel, simulate cases of hall ventilation in room. This wind tunnel can achieve avariety of case of the experiment through the change of window’s area and draught fan’sflow. In the experiment, by testing full differential pressure on either side of the windowprofile, air volume and so on, we research the characteristics of window’s dischargecoefficient, discuss how the window’s opening rate, the flow of air through the room, the airflow path inside the room to affect window’s discharge coefficient.The result of research prove that the discharge coefficient of the window relate to window’sopening rate, the flow of air through the room, the air flow path inside the room. When thewindow’s opening rate is big, the window’s discharge coefficient has nothing to do with theflow of air through the room, at this point, the air flow path inside the room has a little effectson the window’s discharge coefficient. When the window’s opening rate is small, thewindow’s discharge coefficient increases with the flow of air through the room, at this point,the air flow path inside the room has much effects on the window’s discharge coefficient.Through the experiment, we can get that discharge coefficient of into the wind window is between0.551and0.693. Discharge coefficient of out the wind window is between0.141and1.131.