The exposed area and CC � values were calculated by determining the curtain wall and shade position at each movement state . The VF was calculated by averaging solid angles at 400 points ( �� 400 ) spaced at equal intervals on the exposed glazing area . Table 1 shows the calculation results of the VFs and the exposure coefficient . Except for the sixth movement state , ΩΩ ������ , values on the glazing area were greater than 0.77 . Both movement directions ( i . e . X and Y‐axis ) showed that the VF values gradually decreased as the shade elements opened vertically and horizontally . On the other hand , CC � values gradually increased from zero to one as the shade elements opened .
Table 1 . The view factors and exposure coefficients calculated in this study .
Validation was performed by comparing results between the proposed method with an existing tool . The difference between reduction rates of diffuse solar heat gain by shading device installed on 6 mm clear glass was compared . The reduction rate was calculated by comparing diffuse solar heat gain through shaded glazing with that of unshaded glazing . COMFEN 5 is an evaluation program that enables the calculation of window solar heat gain according to various shading devices . Fixed overhangs and vertical fins can be applied , as can “ wall shades .” Since COMFEN cannot be applied to all shading states from 1 to 11 , only state 11 was adopted as a validation case . The result of the validation showed that the proposed method and the existing tool have the same value . The reduction rates both derived the value 0.2 .
Fig . 5 shows the calculation result of the CC � VVVV values according to the shading state . The result of both directions ( X and Y‐axis ) showed that both values were similar at the equivalent displacement step . The values in X‐axis angle change were a little higher than Y‐axis angle change in all states .
Figure 5 . The CC � * VF values according to the shading state .
87 ZEMCH 2019 International Conference l Seoul , Korea