Thermal influence caused by the vertical distribution of reflected solar radiation and re‐radiation on the building in various climate areas and its solar shading method

摘要

Most houses in Japan have the floor‐length windows to take the natural light into the room. Reflected solar radiation and Re‐radiation from the ground (Reflection) enter through the window and increase the cooling load, therefore reducing reflection to the building is necessary. We focused that reflection is greatly affected by the ground surface, its heat flux may vary depending on the height from the ground. This study presented the thermal influence by the vertical distribution of reflection on the building in various climate areas and considered the solar shading method based on that distribution. The calculation results using Sol‐Air Temperature showed that the incident heat flux of reflection increased on the lower part of the building surface, and the vertical distribution of reflection existed in various areas. We propose to shield up to the lower half part of the building as a solar shading method considering the vertical distribution of reflection. This method could be able to shield most of reflection and incorporate natural light from the top half of the window to ensure room brightness and view, that is expected to be effective in improving indoor comfort and reducing the load of cooling and lighting. This study aims to present the thermal influence by vertical distribution of reflected solar radiation and re‐radiation (Reflection) on the building in various climate areas and consider its solar shading method using the thermal load simulation and experiment. The results showed that the thermal influence increased on the lower part of the building surface by the vertical distribution of Reflection in various climate areas in Japan. We consider that shielding up to the lower half of the window is effective in improving indoor comfort and energy saving of the buildings as an efficient solar shading method considering reflection.