New assessment method for solar radiation effects on indoor thermal comfort based on scalar irradiance – Using volume photon mapping

Keita Matsuda, Kaichi Nozaki, Roland Schregle, Kozo Takase, Keiichiro Taniguchi, Nozomu Yoshizawa
Building and Environment, Volume 243, 2023, 110662
https://doi.org/10.1016/j.buildenv.2023.110662

Abstract
Solar radiation has a significant impact on the thermal comfort of office occupants and hence it is necessary to consider its influence during the early design stage. However, with rising complexity of room geometries and solar shading/redirecting systems in fenestrations, it has become increasingly difficult to predict the effects of solar radiation on office occupants intuitively and with high level of accuracy. Therefore, a new method focusing on the visualization of the effect of solar radiation, calculation under complex conditions, and computational load has been investigated in this study. An analysis for thermal comfort using a method based on volume photon mapping by RADIANCE that can visualize and efficiently quantify the effect of solar radiation based on scalar irradiance was validated. As a result, it was further confirmed that the value corresponds to the ERF_solar, which indicates the thermal comfort considering solar radiation, as given in ASHRAE Standard 55. The findings are expected to help designers intuitively and more easily understand the distribution of solar radiation in space to design shadings and perimeter zones in consideration of comfort.