Design and Analysis of a Passive Lighting Device for a Sustainable Office Environment in Hot-Arid Climate Conditions

Visual comfort in office spaces improves not only productivity and wellbeing but also satisfaction and energy efficiency of the buildings. The objective of this research is to study the effect of one of the transporting daylighting systems (Anidolic Integrated Ceiling ‘AIC’) on the enhancement of the luminous interior environment and energy saving in office building through objective and subjective evaluations. The quantitative study was performed by measurement of the illuminance values in the physical model (1:4) under local luminous climate in two scenarios (with and without ‘AIC’) and by numerical simulation to calculate the daylight autonomy. The qualitative evaluations were achieved by using a field survey composed of four questions related to pleasantness, level of light and artificial lighting needs. Experimental study shows that the AIC offers high levels of illumination in quantitative terms result in moderate values of Daylight Factor (2% - 4%). Simulation results showed that more than 88% of energy consumption for electrical lighting can be saved. Subjective evaluation results indicate that in the test model (with AIC), 67% of participants felt more pleasant with the luminous environment, 74.19% considered that the level of light is sufficient and only 08 of 31 subjects need to use artificial lighting

Study of land use/cover change impacts on thermal microclimate using QGIS in urban agglomeration

Thermal comfort and air quality are major concerns for people living in urban areas. In the last decades, cities are growing quickly and the increased urbanization is leading to the expansion of cities, which changes the properties and composition of the landscape. However, the surface temperatures are increasing, globally, because of anthropogenic climate change. Land use and land cover change have been shown to have a significant effect on climate through various pathways that modulate land surface temperature and rainfall. The objective of this study is to understand how the land use and land cover change affects the thermal microclimate in the city of Biskra (Algeria) using QGIS for the period between 2010 and 2020. The analysis results reveal that the mean temperature of the city has increased by ~4 °C during the past decade with the most accelerated warming (~7 °C) occurring during the recent decade (2010 to 2020). Our study shows also that 32% to 56% of this observed overall warming is associated with land use/cover and the largest changes are related to changing vegetation cover as evidenced by changes to both land use and land covers classes and normalized difference vegetation index (NDVI)

Towards a new model of light quality assessment based on occupant satisfaction and lighting glare indices

This study looks at the effect of daylighting on human performance. It includes a focus on glare index combined with the actual feeling of users of the classroom as a way to assess indoor lighting quality. The main objective of this research is to understand the impact of daylighting from windows on the glare sensation and also to determine which glare index is the closest to human visual sensation under local daylighting conditions in Biskra, Algeria with highly luminous climate. The study used High Dynamic Range (HDR) photography, Evaglare and Aftab Alpha software to calculate the two glare metrics Daylight Glare, Index (DGI) and the Daylight Glare Probability (DGP). A survey was also used with 90 occupants under different lighting conditions (different configurations) in a design classroom. In order to link the mathematical model and the human assessment of glare, statistical regression analysis was used. We established a statistically compelling connection between daylighting and student performance

Developing neural networks to investigate relationships between lighting quality and lighting glare indices

The present work compares the ability of the two most used glare indices, the Daylight Glare Probability (DGP) and the International Commission on Illumination (CIE) Glare Index (CGI), using Multiple Correspondence Analysis (MCA) and Artificial Neural Networks (ANN). The research investigates the efficiency of indexes in predictive indoor lighting quality. This study was carried out by analyzing data from a survey administered to ninety students in real design classrooms in the city of Biskra, Algeria. The experiment was conducted using three different lighting indoor conditions: natural and artificial lighting and mixed lighting. The true prediction of the Daylight Glare Probability for the variable Comfortable was 60.60%, and for (CIE) Glare Index the prediction values were equal to 44.60% for the same variable

The virtual environments lighting quality assessment using the virtual reality

The computer simulation field opened up new application opportunities in architecture in the last decades. In particular, Virtual Reality (VR) and Immersive Virtual Environments (IVEs) enable to study the subjective experience in-vitro. This paper investigates the ability of VR coupled with immersive devices in providing users with a better spatial lighting understanding. The goal is to reason about the potentiality of VR and IVE on the lighting quality assessment studies involving final users. The research was carried out by analysing and comparing data of the spatial and lighting perception of users using conventional devices frequently used by researchers in the lighting field for running experiments: screens, video projectors, and VR. Three different virtual lighting conditions in a virtual environment were presented, and a survey was administered to twenty-six participants. Results show that immersive VR allows obtaining more significant correlations between lightning variables than the other devices. Besides, the statistical analyses highlight that VR navigation with immersive devices is associated with an overall better lightning perception of the virtual model than the other non-immersive devices tested in the experimentation. The findings also show that users prefer the immersive environment

Paramètres physiques Des ambiances lumineuses : Un modèle numérique pour l’évaluation des ambiances lumineuses.

De nos jours les standards internationaux d’architecture et de qualité d’espace créés par les concepteurs, accordent une attention de plus en plus importante à l’usager, particulièrement aux sensations approuvées par les usagers, lors de l’exercice des différentes activités affectées à l’espace : bureaux, salles de dessin, bibliothèques, cela sous différents environnements physiques été/hiver, matin/après-midi, etc. Cette grande préoccupation de l'impact de l'environnement bâti sur les occupants à la fois architectural et psychologique, ce traduit par des études approfondies dans le domaine de la psychologie de l’environnement qui visent à comprendre les relations à la fois très importantes et complexes du duo : homme / environnent physique. Notre travail de recherche s’inscrit dans cette même logique, qui vise à étudier et à quantifier l’impact de l’environnement lumineux physique, sur les usagers de l’espace. Notre étude a eu lieu dans les locaux de l’Université de Biskra, qui se situe dans le Sud-Est de l’Algérie, la ville est caractérisée par un ciel mi couvert. L'étude s'est déroulée dans une salle de conception assistée par ordinateur (C.A.O) du département d’architecture de l’Université, cette dernière a une forme de quart de cercle avec un rayon égal à 10 m, la salle est aménagée avec cinq tables hexagonales, qui accueillent six postes de travail chacune, et offrent six diverses orientations, avec un total de trente postes de travail pour l’ensemble de la salle. Afin de varier l’environnement physique « lumineux » de la salle, quatre configurations lumineuses ont été proposées : la première configuration lumineuse utilise exclusivement un éclairage artificiel, la seconde utilise un éclairage mixte (naturel / artificiel) mais en appliquant un complément de vitrage sur les fenêtres, dans la troisièmes configuration on a un éclairage mixte « la configuration actuellement utilisée de la salle », dans la dernière configuration on a utilisé exclusivement un éclairage naturel. Afin de quantifier et de comprendre pleinement les interactions des sujets avec leur environnement, trois étapes ont été nécessaires. La première consiste à réaliser une série de mesures in-situ dans la totalité des 120 postes des quatre configurations lumineuses de la salle (C.A.O). Ces mesures visent en premier lieu à évaluer exclusivement l’environnement physique, à travers des mesures photométriques des niveaux d’éclairement et de la luminance sur différents points critiques du champ visuel et dans la salle, on a mesuré par exemple l’éclairement sur : les claviers, le plan de travail, les tableaux, sur les yeux, etc., et pour les luminances, on a mesuré: la luminance du fond de la salle, écrans, murs, etc. Parallèlement à la première étape, on a mené une étude d’évaluation qualitative de la salle, qui avait comme objectif d’évaluer la qualité lumineuse et spatiale de la salle avec ces quatre configurations lumineuses et cela à l’aide d’une enquête par questionnaire soumise à 120 étudiants. Pour les Sample output to test PDF Combine only IV besoin de l’étude on a demandé aux étudiants d’exercer différentes tâches visuelles, généralement liées à la salle (C.A.O) tel que : le dessin à l’aide du PC, lecture de schéma sur la table, etc. et pour chacune des activés réalisées par l’étudiant, il avait à remplir une partie du questionnaire qui a été spécialement alloué à l’activité en question. La dernière étape de notre travail a consisté à faire le lien entre les évaluations qualitatives, celles recueillies auprès des usagers à l’aide des questionnaires et les grandeurs photométriques mesurées dans la salle, pour cela nous avons eu recours à un outil de statistique « SPSS 24 », la procédure d’analyse statistique adoptée se divise en deux étapes ; la premier consiste à dégager les variables qualitatives et quantitatives significatives « pertinente pour l’étude », pour ensuite former des paires de variables significatives. A la fin, nous avons représenté les résultats obtenus sous forme de modèle graphique 3D, qui schématise le champ visuel humain avec les valeurs de luminances et d’éclairement recommandés pour chaque zone du champ, notre modèle comprend sept modèles graphiques, chacun correspond à une activé demandée à l’usager durant notre étude

A Combined Method for an Exhaustive Investigation of the Anidolic Ceiling Effect on Improving Indoor Office Daylight Quality: an Approach Based on HDR Photography and Subjective Evaluations

Lighting quality in office environments is a broad concept that must be taken into account in the design stage to deliver comfortable spaces to reduce workers' stress. Indeed, daylight should be sufficient to perform visual tasks while avoiding excessive brightness, high contrast, or intense sunlight reflections that can cause discomfort glare. This research aims to test the Anidolic Integrated Ceiling (AIC) performance in creating a visually comfortable space by reducing the probability of glare. A combined method was adopted for investigating the influence of the building orientation and the workers' view directions in the different moments of the day in the winter season. Data collection was performed in an experimental environment, i.e., a physical scale model of 1:4 under real sky conditions. Three variables were: (i) the viewer's positions (parallel and face to the window), (ii) the façade orientation, (iii) the time of the day (morning and afternoon). To investigate the correlation between the simulated environment and the subjective comfort, we collected the following data in parallel: illuminance level, Daylight Glare Probability Index (DGIP), Luminance Contrast Ratios (LCR) for assessing the daylighting environments, and people reactions to the lighting setting to evaluate the perceived discomfort glare. The findings indicate that the Anidolic system's performance differs according to the occupant's orientation and herhis visual direction. The performance of the north façade of the case study application in Biskra, Algeria, was the best one. Indeed, the AIC system allows a harmonious luminance distribution without creating discomfort glare. Glare assessment shows that glare is perceived imperceptible in the lateral view (less than 0.30) and varies between imperceptible and perceptible in the parallel view (LCR values between 1:1 and 1:29). The questionnaire results show that the subjects were more satisfied with the luminous atmosphere of the lateral view than the parallel view where people more likely perceived discomfort. The statistical analysis shows that participants' perceptions of contrast and sensitivity to glare have a strong relationship with DGIP and LCR (0.000) and no correlation with illuminance and LCR

Influence of scale on the daylighting system evaluation in physical models: Experimental method based on objective and subjective measurements

The daylight evaluation in architectural spaces can be carried out using several tools and methods of investigation and analysis. However, many types of research have proven the usefulness of the scale models to evaluate daylighting system performances in buildings. Several scales of a physical model have been used varying between (1:50) and real scale (1:1), and no comparative study has been done to evaluate the effect of the model size in daylighting assessment. The objective of this investigation is to make a comparison between two different scales of a physical model: the first one is a model with a scale of (1:12) while the second is with the scale of (1: 4), aiming to study the scale effects on daylight perception with models equipped with a daylighting system under very high exterior illuminance levels. The methodology of this study consists in collecting simultaneously the measurement of the exterior and interior illuminance level (lux) and subjective evaluations from a questionnaire survey with the two scale models (1:4 and 1:12) under real sky conditions. A correlation between collected data has been explored. Comparing the measurement results, it is obvious that the quantity of light that penetrates the test models (1:4 and 1:12) was the same. The results are with a range of ±1.6%. Moreover, survey results show that the participants’ perceptions regarding satisfaction, light distribution and glare questions differ with the scale of the physical 3D model. The subjects felt more satisfied with the luminous atmosphere with the physical model of (1:4) compared with the model of (1:12)

Évaluation quantitative et qualitative du système anidolique sous un climat chaud et aride

The system presented in this study, called Anidolic integrated ceiling (AIC) is one of the advanced Day lighting systems used to capture, channel and distribute day lighting to the interior space. The present paper gives a quantitative and qualitative evaluation of anidolic integrated ceiling. This device was designed with regard of luminous climate of the city of Biskra (Algeria), installed in the north façade and their luminous performance is assessed experimentally by using scale model, for a 12m deep room. The results of this experimental analysis have shown that the Anidolic Integrated Ceiling offers a great potential for increasing the illuminance level in deep-plan building under hot and dry regions (intermediate sky conditions). In addition, the spherical image shown that the integration of this system provides a good ambiances result by uniform luminance distribution throughout the room which produces a visual satisfaction compared to the reference model

Évaluation quantitative et qualitative du système anidolique sous un climat chaud et aride

The system presented in this study, called Anidolic integrated ceiling (AIC) is one of the advanced Day lighting systems used to capture, channel and distribute day lighting to the interior space. The present paper gives a quantitative and qualitative evaluation of anidolic integrated ceiling. This device was designed with regard of luminous climate of the city of Biskra (Algeria), installed in the north façade and their luminous performance is assessed experimentally by using scale model, for a 12m deep room. The results of this experimental analysis have shown that the Anidolic Integrated Ceiling offers a great potential for increasing the illuminance level in deep-plan building under hot and dry regions (intermediate sky conditions). In addition, the spherical image shown that the integration of this system provides a good ambiances result by uniform luminance distribution throughout the room which produces a visual satisfaction compared to the reference model