Lighting characteristics of complex fenestration systems

The need for energy conservation in buildings has spurred innovations in window technologies. These products include windows combined with shading devices, and windows featuring complex glazings such as smart glazings, translucent and transparent insulation, patterned or decorative glass. Unfortunately, little is known about their impact on the quality of the indoor environment. This paper addresses the development of new lighting quality indices for the outdoor view (which gives a feeling of connection to the outside), indoor view (which may affect feelings of privacy), and window luminance (which indicates the potential risk of discomfort glare). The new indices were applied to a typical fenestration system, consisting of a clear window equiped with an interior perforated shading screen with opaque and translucent materials. The simulation results indicate that the the light-coloured screen has a significant impact on the outdoor view and window's luminance, depending greatly on the sky conditions. Under clear sky conditions, the window's luminance may be increased by up to 80% compared with overcast sky conditions, particularly for a window with a translucent screen.La n\ue9cessit\ue9 de conserver l'\ue9nergie dans les b\ue2timents a engendrer des innovations dans la technologie de la construction des fen\ueatres, notamment les fen\ueatres dot\ue9es de dispositifs d'ombrage et les fen\ueatres \ue9quip\ue9es de vitrages complexes tels que le vitrage intelligent, les isolants translucides et transparents, ainsi que le verre imprim\ue9 ou d\ue9coratif. Malheureusement, on en sait bien peu sur leurs incidences sur l'environnement int\ue9rieur. Ce document traite de la cr\ue9ation de nouveaux indicateurs de la qualit\ue9 de la vue sur l'ext\ue9rieur (qui procure un sentiment de rapprochement avec le milieu ext\ue9rieur), de la vue sur l'int\ue9rieur (qui peut influer sur le sentiment d'intimit\ue9) et de la luminance des fen\ueatres (qui indique le risque possible d'\ue9blouissement d\ue9sagr\ue9able). Les nouveaux indicateurs ont \ue9t\ue9 appliqu\ue9s sur un ensemble type de fen\ueatre constitu\ue9 d'une vitre claire et d'un \ue9cran perfor\ue9 interne compos\ue9 de mat\ue9riaux opaques et translucides. Les r\ue9sultats de la simulation indiquent que l'\ue9cran p\ue2le influence de fa\ue7on significative la vue sur l'ext\ue9rieur et la luminance de la fen\ueatre selon l'\ue9tat du ciel. Par ciel clair, la luminance de la fen\ueatre peut augmenter jusqu'\ue0 80 % par rapport aux observations par ciel partiellement couvert, surtout dans le cas d'une fen\ueatre \ue0 \ue9cran translucide.Peer reviewed: YesNRC publication: Ye