The effect of shading design and control on building cooling demand

Shading provision should be considered as an integral part of fenestration system design for commercial and office buildings, in order to balance daylighting requirements versus the need to reduce solar gains. Utilization of daylight in buildings may result in reduction in electricity consumption for lighting but also in high cooling demand if excessive solar gains are admitted in the working space. Moreover, visual comfort should be ensured especially for perimeter office spaces. Shading devices can control solar gains and simultaneously allow adequate daylight to the interior. In this paper, the simultaneous effects of shading device properties and control on building cooling demand are evaluated using a coupled lighting and thermal simulation module. The interactions between cooling and lighting energy use in perimeter spaces are analyzed as a function of window-towall ratio and shading parameters. Roller shades are used as an example. Shading device type, properties and control have a significant impact on building cooling demand. An integrated approach for dynamic operation of fenestration systems in conjunction with controllable electric lighting systems could lead to minimization of energy consumption for cooling in perimeter spaces, depending on climatic conditions and orientation.