Daylighting, facades, dynamic controls, simulation tool
Previous studies studied the impact of static and dynamic fenestration systems on daylight performance and energy use in perimeter building zones. Advanced daylighting metrics and overall lighting performance can be calculated for spaces with different façade characteristics, controls and orientations. It has been shown that dynamic solutions may result in energy savings while maintaining visual comfort but there are limited sources of information for a comprehensive daylighting “guidebook”. This paper presents the development of a daylighting performance guide for perimeter office spaces in North America. An advanced lighting simulation model, validated with experimental results and verified advanced tools, is used to calculate annual performance indices and daylighting metrics for perimeter spaces in different climates. The model flexibility allows parallel investigation of several parameters (window-to-wall ratio, glazing optical properties, shading properties and controls) and extraction of dynamic performance metrics, since these parameters can directly relate to energy use, visual comfort and lighting uniformity. A highlight of this tool is the ability to model and produce results for dynamic façade systems for which the daylighting performance is difficult to assess using simplified tools or publicly available daylighting software. A guide tool with a simple interface was also developed to help designers and architects make appropriate decisions about façades and daylighting. The tool outputs include dynamic spatial daylighting metrics, comfort indices and lighting energy use for perimeter zones in different climates for a variety of façade parameters. The powerful engine can be also used to establish multivariate correlations for evaluating the combined impact of façade design decisions during the design stage with respect to daylighting performance.