1987 Volume 12 Issue 35 Pages 73-83
The solar shading characteristics of a window with a roll curtain are discussed. Two box style experimental equipments were made to examine the solar shading ability of windows and heat transportation of air flow through side slits between the window and the roll curtain. The quantitative estimation of the air flow heat transportation makes it possible to divide the solar shading effect of the roll curtain into the effect of transmission, radiation, convection, and ventilation. The results in this paper are as follows: 1) One experimental box was made for outdoor experiments to examine air distribution of the space between the window and the roll curtain. Air flow comes in from the lower part of side slits and goes out through the upper part. In the central area of the window, air turbulence caused by ventilation is small so that there is temperature stratification of air in case of low velocity indoor air flow near the roll curtain. In case of rather high velocity (0.7〜0.8m/s), the temperature stratification of air is broken, but the air turbulence is small when the width of slits is about 5mm. 2) The other box was made for the indoor experiments. It can measure the convective heat transportation through the slits by replacing the solar heat absorbed by a window glass pane heat generation within the glass. The value of the transported heat is shown in the chart which uses the width of the slits and the distance of the window and the roll curtain as parameters. 3) Solar heat gain coefficient (SHGC) of window to which a solar reflecting film was attached were compared with inside pasted film, a window with outside pasted film, a window with tightened air space. As a result, the SHGC of the window with the roll curtain is smaller than that of the window with inside pasted film, and the effect of roll curtains made of high solar reflective material is proved.
