Daylight In Spaces Research Articles

Assessment of building façade performance in-terms of daylighting and associated energy consumption in architectural spaces

This paper examines the effect of vertical and horizontal shading devices on the quality of daylight in buildings and the associated energy saving. Excessive daylight in architectural spaces contributes negatively to the energy consumption in buildings. Blinds and shading devices are good solutions to attenuate the surplus amount of daylight in spaces. Accordingly, this study evaluates the effect of shading devices on the amount of light flux and the associated solar energy in buildings. It estimates the energy consumption attributed to lighting spaces for three common positions of shading devices. Computer simulation strategy was undertaken to correlate the illuminance level in spaces with room geometry and architectural shading elements. The Holophane model for lighting calculations was used to estimate the average illuminance level on workplane and correlate it with the expected saving energy in buildings. The study concluded that there is an optimal orientation for shading devices that keeps the internal illuminance level within the acceptable range with minimum amount of solar heat gain.Keywords: Shading device, Daylight Illuminance, Heat gain, Computer simulation, Energy consumption

Atrium and its adjoining spaces: a study of the influence of atrium façade design

Atrium buildings have been unsuccessful in utilizing available daylight in spaces adjoining the atria. Several studies indicate the potential to improve daylight in adjoining spaces through glazing distributions of progressive increase in the amount of openings from the upper to the lower floors in medium-scale atria. The aim of this investigation was to study parametrically the effects of glazing variations in the façade on daylight factors (DFs) in the atrium and its adjoining spaces under overcast sky conditions. Using Ecotect and Radiance, the objective was to provide optimum glazing ratios for a four-sided, top-lit, square atrium building of WI 0.8. Three glazing compositions were evaluated according to the progressive increase in openings. Each composition, presented as curves, comprises five options worth 20, 30, 40, 50 and 60% openings on the top floor with a progressive increase until 100% opening is reached on the ground floor. The study concluded that façade compositions have almost no influence on the lower floor adjoining spaces where more daylight is typically required, but can have significant influence on the top two floors. Having very small windows on the top floor (20%) increases DFs in the adjoining spaces; however, this increase is not significant and compromises light levels on the top two floors. In this study, the option of 60% opening on the top floor, 79% opening on the fourth floor, 92% opening on the third floor, 98% opening on the second floor and 100% opening on the ground floor was recommended, as it increased DFs on the top floors without compromising on DFs on the lower floors.

Assessment of building façade performance in terms of daylighting and the associated energy consumption in architectural spaces: Vertical and horizontal shading devices for southern exposure facades

This paper examines the effect of vertical and horizontal shading devices on the quality of daylight in buildings and the associated energy saving. Excessive daylight in architectural spaces contributes negatively to the energy consumption in buildings. Blinds and shading devices are good solutions to attenuate the surplus amount of daylight in spaces. Accordingly, this study evaluates the effect of shading devices on the amount of light flux and the associated solar energy in buildings. It estimates the energy consumption attributed to lighting spaces for three common positions of shading devices. Computer simulation strategy was undertaken to correlate the illuminance level in spaces with room geometry and architectural shading elements. The Holophane model for lighting calculations was used to estimate the average illuminance level on workplane and correlate it with the expected saving energy in buildings. The study concluded that there is an optimal orientation for shading devices that keeps the internal illuminance level within the acceptable range with minimum amount of solar heat gain.

Daylighting in Atrium Spaces

Atria can be used to serve environmental benefits. This paper studies the effects of daylight in spaces adjacent to an atrium only. The atrium building represents a five storey office building. Light is drawn into the well from the top of the atrium. It is drawn into the side spaces through openings in the wall facades of the atrium well. The relative contributions to the day lighting in the adjacent spaces due to variable opening sizes and surface reflectivity on the wall facades of the atrium, and the surface reflectivity of the atrium floor have been recorded. The respective roles of the atrium walls and floor for enhancing lighting in the well and the side spaces have been studied.