An analysis and simulation of curtain wall reflection glare

This paper presents a computer-aided visualization of the influence of reflected sunbeams from glass curtain wall buildings. A boundary of reflection area (BRA) is proposed as a performance index in the evaluation of reflection glare. BRA is conducted through the computer simulation of a 1×1×1 test cube with four façades made by reflective material. The cube is used to reference the horizontal area that would receive reflections in order to provide the comparison base of evaluation. Due to the symmetric shape of the cube, a butterfly-shaped BRA was concluded. BRA is smaller at the summer solstice than at the spring or autumnal equinox. The BRA is compared at different angles of tilt and orientations of walls. In order to reduce BRA, a passive design approach was applied by tilting walls or rotating plans to evaluate how the tilted angles or orientation of the façade would affect reflected glare. The simulation enabled design evaluation, with an inspection above normal eye level and in a broader area, than that which normally could be achieved in a site survey at a pedestrainʹs or a driverʹs level. The computer simulation verified the influence of reflection on the urban environment by using a time-based record.