The derived CC � VVVV values can be applied to an adaptive façade in all orientations ( East , South , North , West ). Fig . 6 shows the diffuse solar heat gain through a single glazed curtain wall [ W / m 2 ]. The single glazing ’ s solar heat gain coefficient for diffuse component , 〈 SSSSSSSS 〉 � , is 0.737 . Fig . 6 ( a ) shows diffuse solar heat gain without shade , ( b ) shows with shade at state one , and ( c ) shows with shade at state three . The maximum values of hourly diffuse solar heat gain were 230 W / m 2 in case ( a ), 171 W / m 2 in case ( b ), and 72 W / m 2 in case ( c ). As the shade state changed to state six , the diffuse solar heat gain decreased ; it increased as the shade changed to state 11 . The result shows that this method enables users to control the amount of hourly diffuse solar heat gain by adjusting hourly shading states .
Figure 6 . The hourly diffuse solar heat gains through south façade in Seoul , Korea .
The results of the application showed that the combination of the exposure coefficient and the VF can reflect the step‐by‐step movement of the dynamic shade to calculate diffuse solar heat gain through an adaptive façade . This study only focused on the calculation of the diffuse solar heat gain in terms of EMSDs ; to fully evaluate total solar heat gain for an adaptive façade , the direct , diffuse , and ground reflection components should also be considered .
4 . Conclusion
This study focused on calculating diffuse solar heat gain through an adaptive façade . The exposure coefficient and VF were considered major shading factors . The solid angle method was adopted to calculate the unshaded VF at a point on the window . The average VF was then calculated by averaging solid angles at multiple points spaced at equal intervals on the exposed glazing area . Finally , a twodirectional folding type shade was evaluated using the proposed method . The movements of the shade were divided into 11 operational states with equal position displacements . The solid angles were calculated at 400 points on the exposed area in each state to calculate average VFs . The result of the application showed that combining the exposure coefficient and VF can reflect the step‐by‐step movement of the dynamic shade and thereby calculate the hourly diffuse solar heat gain through an adaptive façade .
Although this study focused only on the calculation of the diffuse solar heat gain regarding EMSDs , the proposed method could possibly be applied to the total solar heat gain calculation process and whole building simulations .
Acknowledgements
Funding : This research was funded by the National Research Foundation of Korea ( NRF ), grant number NRF‐ 2017R1A2B2009904 .
References
1 . ASHRAE , ASHRAE Handbook Fundamentals , Chapter 15 ; Amerixan Society of Heating , Refrigerating and Air Conditioning Engineers : Atlanta , GA , USA , 2017 .
2 . Hosseini , S . M .; Mohammadi , M .; Rosemann , A .; Schröder , T .; Lichtenberg , J . A morphological approach for kinetic façade design process to improve visual and thermal comfort : Review . Build . Environ . 2019 .
Calculation Method for Evaluating Diffuse Solar Heat Gains Through Adaptive Façades 88