Paper Conference

Proceedings of BSO Conference 2016: Third Conference of IBPSA-England


Investigation Of The Effective Parameters In Square Unit Based Shading Systems; A Scope Of Achieving Balance Between Daylight And Thermal Performance

Mohamed Saad, Mostafa Atwa

Abstract: The façade of the building is considered as one of the main contributors to the energy requirements of building spaces especially office spaces. Shading is one of the solar protection strategies that was used for long years in the past. Recently, utilizing shading devices increases as a solar protection provider in the hot arid climate in Cairo. Many publications reported the positive effect of square-based egg-crate shading devices on both daylighting performance and thermal performance. Different parameters as perforation ratio, depth and the grid size of egg-crate systems could affect the performance on achieving the optimum performance visually and thermally. Therefore, this research aims to carry out a deep investigation on the effect of these parameters of the egg-crate shading system in order to improve the performance of the shading system. Brute-force parametric simulation was conducted in the form of predefined algorithms using different proposed parameters in order to conclude the optimum solutions for the studied window to wall ratios. Grasshopper plugin for Rhinoceros was utilized for carrying out the parametric modelling process of all the different design configurations of the studied shading device. The study adopted a simulation process constructed on two sequential phases, which were carried out using DIVA for Rhino the interface for the widely used simulation engines Radiance, Daysim and EnergyPlus. Moreover, the simulation was derived based on the IES approved daylight metrics, particularly Spatial Daylight Autonomy (sDA) and Annual Sunlight Exposure (ASE). Results carried out the optimum composition associated with specific WWRs, which improves the distribution of daylight and complies with LEED v4 daylighting standards. Finally, analysing results of the study revealed many findings regarding the potential of using the egg-crate system and screening the effect of each parameter. Evaluation process of the study was carried out.
Pages: 419 - 426