On the combined use of laser-cut panel light redirecting systems and horizontal blinds for daylighting and solar heat control, a focus on visual comfort objectives

Aiming to explore its performance as energy efficient system, in this study, the window is subdivided according to functions, in which the upper part would act as a daylight optimization unit. Two variant positions of lasercut panel, known as ‘louvre-style’ and ‘venetian-style’ are placed in the upper window unit, in order to take advantage of their angle selective redirecting capabilities. Their effectiveness to provide a satisfactory visual comfort is evaluated by assessing their potential for solar control and daylight redirection indoors. The first results indicate that the use of lasercut panel as a sole system, its insufficient to provide an adequate visual environment, with a reduced risk of glare for the occupants. Aiming to improve its performance, horizontal blinds are added as supplementary element to the interior-upper part of the window, blended in an arrangement called ‘secondary system’. As a result of a comprehensive evaluation, in which, the upper and middle window units are considered, two lasercut panel styles are identified as those providing sufficient daylight provision indoors, and a reduced risk of discomfort glare. The properties of the fenestration systems tested here, were described using their corresponding BSDF data, while the evaluation was performed using the RADIANCE matrix multiplication methods