Investigations On Thermal Protection In Summer - Part 3: Modeling Of Complex Geometries And Different Material Properties Of Shading Systems

A series of three articles investigates the thermal protection of buildings in summer using different methods and boundary conditions. Part 1 compares the code compliance methods prescribed by DIN 4108-2 and considers future climate data. Part 2 deals with multi-dimensional approaches to model shading systems. Part 3 presents a new approach to model shading systems that consist of non-standard geometries and highly -reflective materials.In part 3 external shading systems are investigated with respect to their geometry and material properties using the method of BSDF matrices which has been presented in part 2. One focus of the investigation is set on the choice of the calculation approach to generate the BSDF. The radiosity approach is compared with numerical raytracing as means to generate the necessary metrics in the shortwave and longwave range of radiation. Based on the building simulation results the impact of the chosen method as well as the influence of different geometries, highly reflective surfaces, and a low-e coating on the back side of the blinds is assessed. Finally, the resulting differences are put into the context of code compliance calculations regarding thermal protection of buildings in summer time.