Paper Conference

ASHRAE & IBPSA-USA SimBuild 2016: Building Performance Modeling Conference


Daylight Glare Analysis for an All Glass Cathedral: Integrating Simulation with Common Sense to Improve Visual Comfort

Chanyang Shin, Greg Collins
Syska Hennessy Group, New York, NY
Syska Hennessy Group, Los Angeles, CA

Abstract: Visual comfort in heavily glazed indoor environments is a growing concern in contemporary architecture. Significant progress has been made toward understanding and even quantifying daylight glare using modern software tools. The simulation tools are proficient in their evaluation of daylighting glare conditions. However, the creative design process and the pace at which decisions must be made do not lend themselves to the iterative, simulation-based workflow that practitioners have become accustomed to. The process with which to validate proposals and optimize solutions, therefore, must combine intuition and experience alongside analytical horsepower, and perhaps a traditional sun path diagram. The Christ Cathedral (formerly known as the Crystal Cathedral") is an existing all-glass structure in Orange County California-an exemplary case study in glare simulation. The building walls and roofs consist almost entirely ofcurtain wall so the building energy and daylighting performance was incredibly sensitive to the strength and position and of sun. A glazing replacement was ruled out early on, so the design team developed a system of interior panels to serve not only as aesthetic components to enhance visual diversity, but also as shading devices to reduce the excessive daylight exposure to future occupants. The basic design condition was evaluated using DIVA for Rhino for daylight glare analysis based on geometric information gathered from the architectural 3-D models and local climatic data. The iterations of analysis simulated solar position throughout the day and year, intolerable glare hours using Daylight Glare Probability (DGP) as a main metric, and various RADIANCE simulations to identify specific issues at critical points in time. The simulation helped detect problematic times and areas where glare issues occurred. Focused more on the detected time and area, each shading panel was analyzed in a small scale with 2D Sun angle diagraming, in order to find out how the design could be improved. Several alternatives for the shading panels, which came to be known as “quatrefoils,” and
Pages: 267 - 274