Since our society has grown rapidly for a few centuries, the big cities have been appearing in the world. The cities are playing a important role to lead our society, but on the other hand they bring with them many environmental problems. One of the p...
Since our society has grown rapidly for a few centuries, the big cities have been appearing in the world. The cities are playing a important role to lead our society, but on the other hand they bring with them many environmental problems. One of the problems is specular reflection from the curtain walls of high-rise buildings. The high-rise buildings were built in response to increasing population, shortage of land, and advances in architectural engineering. Additionally, some architects wanted to make modern architecture using glass in building facades.
In the end, though, many problems have resulted from the curtain wall. Especially low-emissive glass is a main reason that causes specular reflection and thermal discomfort in adjacent areas during daytime throughout the year. Today architects have to consider the light environment in the neighborhood when they choose the exterior material. In point of fact, specular reflection occurs on the smooth surface of glass. Rough glass doesn’t create such specular reflection. Thus, we know that roughness is significant factor in the scattering of light and determines the scattering characteristic.
Therefore, our research made rough plate glass which is sorted by degree of roughness that can be an option to reduce specular reflection from sun light. To control the surface roughness, we used sand blasting. It is a simple way to produce rough plate glass among the many other methods for controlling glass roughness. Such a countermeasure also reduces the transmittance of sun light and contributes to cooling load reduction in the building. Controlling the surface roughness of glass has been researched constantly in physical optics. In this paper, we investigate the relationship between roughness and specular reflection of glass through reflectance, transmittance, the bidirectional reflectance distribution function (BRDF) and the bidirectional transmittance distribution function (BTDF).
Therefore, our research aims to provide fundamental information on specular reflection from surface roughness of glass in a curtain wall and contribute to the reduction of specular reflection.