The Experimental Study On The Sunshading And Opening Or Closing Performance Of Ventilated Breathing-type Glass Curtain Wall

As one of the modern buildings envelops, breathing-type glass curtain wall is not only beautiful and penetrating, but also with the characteristics of summer heat insolation and the winter heat preservation. It can decrease energy consumption of building. Its function of improving the inner thermal environment is closely related to its reasonable use; therefore, it is of great significance to research on the sunshading and opening or closing performance of ventilated breathing-type glass curtain wall.In this project, Tianjin is chosen as the representative of the cold regions; the energy conservation center which takes the breathing-type glass curtain wall as the outer building envelop is taken as the object of the study. The author has conducted experimental study on the impact that the curtain has on the indoor thermal environmental throughout the year. In summer the author mainly carried out experiments of the impact of sandwich with or without blinds, blinds blade angle, the relative position of channel and other factors on indoor thermal environment. In winter he studied experimentally the impact of the different opening and closing ways of vents of inner and outer curtain walls on the indoor thermal environment. And in spring and autumn, the transitional seasons he studied the impact of all those four factors mentioned above on the indoor thermal environment.The conclusion is drawn through the experimental data analysis of different conditions throughout the year. In transitional seasons(the end of spring), the sandwich-sunshade can reduce the indoor temperature, and improve the indoor thermal environment. When the sunshade is close to the outer curtain, its function of improve the indoor thermal environment reaches its maximum. When the angle of blade and earth is about 45°or 135°, the shading effects are much close, and they are both better than those when the blades are parallel to the ground. In summer, the temperature of a blade-fully-closed room is lower than that of a sun-room. The biggest temperature difference can reach 2.5℃, and the temperature changes slightly in a sun room throughout the day; when being in the position of nearing the internal facade, the blinds’ function to improve the indoor thermal environment reaches its peak; the effect of changing the indoor thermal environment would be the best when the blades and the ground form the angle of 135°; while the worst effect would appear if the angle is 0°. During the transitional seasons(early spring), under the circumstances that the air-windows of internal and external facades are closed, the use of breathing-type glass curtain wall has a small part to play in the indoor thermal environment and just delay the increase or decrease of temperature; the best opening method is to open bottom air-windows of external facades all the day, and open the air-windows of inner facades in the daytime; therefore, the demands for indoor thermal comfort ability and fresh air will be satisfied. In winter, opening air-windows of internal facades in daytime can effectively raise indoor temperature and reduce indoor heating load; the best opening way is to keep the air-windows of external facades closed all the time; the air-windows on internal facades open when the temperature of channel increases to the indoor temperature in the morning; and the air-windows close when the temperature reduces to the indoor’s in the afternoon.