Subdivided Windows with Mixed Shading Devices: A Daylighting Solution for Effective Integration of Occupants into the Building Environmental Control

Abstract

Daylighting is one of the most challenging aspects of an ecological building design. The dynamic nature of daylight along with a wide range of individual preferences makes it a complex design issue. The art of daylighting relies on fine-tuning a delicate balance between admitting sufficient daylight for occupant well being and task performance and preventing glare and over heating. These goals are rarely achieved in buildings where fenestration design is reduced to an opening with an interior blind due to occupants' infrequent shade operation. To address this problem, a number of automatic shading devices have been developed to be integrated with the lighting control system for an optimized daylit environment. Although such systems reveal substantial energy savings in laboratory and energy modeling tools, evidence has accumulated that they do not perform well in real buildings and disregard occupants' need for perceived control over their environment. This dissertation aimed at examining the potentials of a subdivided window in solving the current challenges of daylighting side-lit spaces. The field observation suggested that a subdivided window with horizontal shading devices increases occupants' chance of raising the blinds and reduces their lighting energy consumption. The simulation studies established that subdivided windows combining automatic and manual shading devices have the potential to significantly reduce the lighting energy use and maintain a well-daylit environment throughout the year.