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For the application of discomfort glare metrics, a categorisation is used, dividing the metric scale into categories of perception. These categories are separated by borderline values, or so-called cut-off values. Recent literature shows that these cut-off values are lower when they are derived from field study data than those derived from laboratory study data. To investigate this further, the data from one field study and two laboratory studies was used to derive and compare cut-off values corresponding to three borderlines. The results show that the field study cut-off values were systematically lower than the laboratory study ones, implying that discomfort glare is reported at lower stimulus magnitudes in the field. Although further research is required on that topic, several hypotheses are discussed in order to explain the gap between cut-off values derived from field data and cut-off values derived from laboratory data. Recommendations for future studies are also provided.

Exposure to light, and especially to daylight, has much to offer. Regarding buildings’ occupants, daylight has been shown to boost performance, improve sleep, provide a connection to the outside, increase comfort, lessen agitation, and reduce depression. Regarding buildings, daylight enhances the aesthetics of a space and improves its energy efficiency. On one condition, though: that it does not produce visual discomfort. In order to harvest the benefits of daylight, visual discomfort has to be minimized. Hence, discomfort glare from daylight should be predictable. To date, more than twenty daylight discomfort glare models have been developed. However, none of them can consistently and accurately explain the large variation between subjects’ discomfort glare perception. Improving current models predicting discomfort glare perception remains a crucial step to move towards optimal daylighting design in buildings. In this context, it is hypothesized that the prediction of discomfort glare perception can be improved by including relevant additional factors related to the context or to the subject in the models. The main research question that this study aims to answer is to determine whether one of these factors, namely the socio-environmental context of the subject, influences discomfort glare perception from daylight in office buildings. The socio-environmental context is defined here as the climate and habitat, including indoors and outdoors, to which a subject has been acclimatized, her/his behavior toward these elements, and her/his expectations about them. Two additional research questions aim at investigating other potentially influencing factors and potential experimental biases in order to guide further research in the field. For this purpose, a field study was conducted in real office buildings located in four socio-environmental contexts, i.e., Chile, Belgium, Japan, and Switzerland. Discomfort glare perception evaluations, each consisting of a subjective ass, L’exposition à la lumière, et en particulier à la lumière du jour, a beaucoup à offrir. En ce qui concerne les occupants des bâtiments, il a été démontré que la lumière du jour accroît les performances, améliore le sommeil, assure une connexion avec l’extérieur, augmente le confort, diminue l’agitation et réduit la dépression. En ce qui concerne les bâtiments, la lumière du jour met en valeur l’esthétique d’un espace et améliore son efficacité énergétique. Cela n’est valide qu’à une condition cependant : qu’elle ne produise pas d’inconfort visuel. Afin de récolter les bénéfices de la lumière du jour, l’inconfort visuel doit être minimisé. Par conséquent, l’éblouissement d’inconfort causé par la lumière du jour devrait être prévisible. À ce jour, plus de vingt modèles d’éblouissement d’inconfort dû à la lumière du jour ont été développés. Cependant, aucun d’entre eux ne peut expliquer de manière cohérente et précise la grande variation de la perception de l’éblouissement d’inconfort d’un sujet à l’autre. L’amélioration des modèles actuels permettant de prédire la perception de l’éblouissement d’inconfort demeure une étape cruciale afin d’avancer vers une conception optimale de l’éclairage naturel dans les bâtiments. Dans ce contexte, nous émettons l’hypothèse que la prédiction de la perception de l’éblouissement d’inconfort peut être améliorée en incluant dans les modèles des facteurs additionnels pertinents liés au contexte ou au sujet. La principale question de recherche à laquelle cette étude cherche à répondre est de déterminer si l’un de ces facteurs, à savoir le contexte socio-environnemental du sujet, influence la perception de l’éblouissement d’inconfort par la lumière du jour dans les immeubles de bureaux. Le contexte socio-environnemental est défini ici comme le climat et l’habitat, en ce compris l’intérieur et l’extérieur, auxquels un sujet s’est acclimaté, son comportement envers ces éléments, et ses attentes à leur égard. Deux questions de recherche supp, (FSA - Sciences de l'ingénieur) -- UCL, 2019

Because well-being is becoming a major challenge in construction alongside energy efficiency, there is an increasing need to be able to quantify discomfort in buildings. In the case of discomfort glare, the kind of glare provoking an irritating or distracting effect, no current indices can properly explain the high variability existing between individuals’ discomfort glare perceptions. This is due to the fact that some of the factors influencing discomfort glare perception are still unknown and the mechanism behind the discomfort glare process is not well understood. Therefore, this article aims to review the factors potentially influencing discomfort glare perception from daylight. Every factor having been studied at least once for its potential influence on discomfort glare perception has been listed, described, and analyzed. Furthermore, this study categorizes the influence of these factors on discomfort glare by introducing an influence indicator based on the number of studies having investigated the factor, the sample size of these studies, and the agreement between them. The suggested categories rate a factor influence as “almost certain,” “more likely,” “somewhat likely,” “inconclusive,” “somewhat unlikely,” “less likely,” or “almost certainly null.” Tables summarize the main information about the studies and the influencing factors. As expected, factors almost certainly influencing discomfort glare perception are the luminance of the glare source, adaptation level, contrast effect, and size and position of the glare source. In contrast, factors that almost certainly do not influence discomfort glare perception are the gender and optical correction of the observer. All other factors from the list of 30, such as the attractiveness of the view through the window or the culture of the observer, require additional studies to determine whether or not they influence discomfort glare perception.

Nowadays, discomfort glare indices are frequently calculated by using evalglare. Due to the lack of knowledge on the implications of the methods and parameters of evalglare, the default settings are often used. But wrong parameter settings can lead to inappropriate glare source detection and therefore to invalid glare indices calculations and erroneous glare classifications. For that reason, this study aims to assess the influence of several glare source detection methods and parameters on the accuracy of discomfort glare prediction for daylight. This analysis uses two datasets,representative of the two types of discomfort glare: saturation and contrast glare. By computing three different statistical indicators to describe the accuracy of discomfort glare prediction, 63 different settings are compared. The results suggest that the choice of an evalglare method should be done when considering the type of glare that is most likely to occur in the visual scene: the task area method should be preferred for contrast glare scenes, and the threshold method for saturation glare scenes. The parameters that should be favored or avoided are also discussed, although a deeper understanding of the discomfort glare mechanism and a clear definition of a glare source would be necessary to reliably interpret these results.

To collect subjective evaluations of discomfort glare, subjects are usually asked to rate a visual scene on a glare scale. Several glare scales have been defined in the literature, and many replications or derivatives of these scales are currently used. One of the most adopted glare scales is the 4-point Osterhaus’ scale – imperceptible/noticeable/disturbing/intolerable –, although scales that used modified versions of the 5 labels from the 9-point De Boer’s scale – unbearable/disturbing/just admissible/satisfactory/unnoticeable – are also common. Unfortunately, it is frequent practice by some experimenters to either mix labels from different scales or develop their own glare scale, hence making between-studies comparisons very difficult. There is a large consensus between researchers that most glare scales are unipolar, going from a “no glare” to a “very glary” end. These scales are usually treated as such in statistical analyses and for their correlation with discomfort glare indices. But, how do the subjects interpret these scales? Up to now, there has been only one study investigating subjects’ interpretation of a modified De Boer’s scale. The results showed that, besides the confusion brought by the terminology, only 15% of the subjects could reconfigure the labels of the scale in the right sequence. In an effort to clarify the use of glare scales, the data from two field studies have been analyzed.

This paper presents a research about the possibility to use a scale model of a room to assess the luminances in the visual field of the room's user, and consequently its risk of glare. Measurements of luminance values by the HDR technique were done simultaneously in a room and its 1/6 scale model, with identical measurement material. The room was lit by a lateral window either unprotected from direct sun radiation, or fitted with a white or black screen. Measurements show that luminance values obtained in the scale model are overestimated and that the relative differences between values in the scale model and in the mock-up vary between 10 and 50% for the situation without shading device, between 45 and 80% for the window equipped with the white screen and between 0 and 45% with the black screen. Yet, the evolution of luminances is very similar for both rooms, and a high level of correlation is observed between glare index DGP values calculated on these respective luminance values, despite a very slight over-evaluation of the DGP in the scale model. In conclusion, for the situation tested, the DGP can be evaluated using a 1:6 scale model, under the condition of very accurately respecting the geometry and photometric data of the studied room walls. It is also very important to position the scale model in a way to obtain a view on the outside as similar as possible to the one obtained from the studied room.

A l’heure actuelle, les problèmes environnementaux et la sobriété énergétique sont deux enjeux majeurs de notre société. Alors que chacun prend peu à peu conscience de sa responsabilité personnelle et de son devoir par rapport aux générations futures, il apparaît que seule la contribution de tous les citoyens aux efforts communs de réduction de production de CO2 nous permettra de limiter les effets de l’activité humaine sur le réchauffement climatique. L’éclairage consomme environ 1/5 de la production mondiale d’électricité. Celui-ci est utilisé pour l’éclairage urbain, l’éclairage industriel, l’éclairage des services tertiaires et l’éclairage résidentiel. Par ailleurs, le secteur résidentiel consomme pratiquement 1/3 de la totalité de l’électricité produite en Europe. Un des domaines sur lequel nous pouvons tous agir est celui de l’éclairage de notre logement, qui représente 5 à 20% de notre facture électrique totale. Alors que de nouvelles directives européennes visent à réglementer les produits en éliminant les lampes les moins efficaces, ce guide de l’éclairage efficace des logements tente de synthétiser les techniques et technologies d’éclairage destinées aux habitations mais aussi de conseiller tout un chacun sur la manière de concevoir l’éclairage de son logement et de discuter de quelques idées reçues concernant les lampes à led.

Luminance maps created on the basis of High Dynamic Range Imaging is a technique increasingly used to study the visual environment. But creating HDR images with commercially affordable equipment requires a tedious calibration process, during which several steps could go wrong without anyone noticing it. This paper aims to provide an overview of the HDR calibration process, including different options, attention points and common mistakes. For inaccuracies and errors to be more easily detected and corrected, it is essential to understand each transformation applied to the images. Therefore, the capture of multiple exposure photographs, the response curve derivation, the HDR image generation, the vignetting and neutral density filter correction, the absolute calibration, and the geometrical reprojection stages are addressed. A more detailed description of the geometrical reprojection, especially required when working on glare assessment, is given as this topic has not yet been dealt with in the literature.

The mechanism behind the discomfort glare phenomenon, the kind of glare provoking an irritating or distracting effect, is not well understood. Since some of the factors influencing this phenomenon are still unknown, no current indices can properly explain the high variability existing between individuals’ discomfort glare perception. A list of potential factors influencing the degree of perceived discomfort glare in daylighting has been established from existing literature. In addition to the physical quantities commonly used in glare indices, other variables, whether psychological, physiological, related to light or to the context, could influence the degree of perceived discomfort glare.

Relatively recent cultural and technological changes, particularly in Westernized societies, have led to habitat and lifestyle shifts that have gradually estranged us from daylight. Although human beings are resilient and appear able to cope with extreme variations in environmental and living conditions, this process of separation can have negative impacts on health and well-being. Further research is essential in order to understand the impact of these changes and to initiate corrective measures, from changes in lifestyle and cultural attitudes to adjustments in the built environment and technology. This section explores these issues and the range of possible solutions.

The Sun is acknowledged as the mother of all light sources: It enables life on earth as we know it. But what is it that makes natural light unique, and most technologically advanced light sources pale in comparison?

The energy consumption in Chile is strongly influenced by the residential sector, with 20% of the total consumption of the country (Gobierno de Chile, 2012a). The Chilean government sets at 30% the reduction potential of the energy used for heating in the residential sector, namely 6% of total energy consumption in the country (Gobierno de Chile, 2012c). Therefore, the residential sector can and must play a key role in achieving the economic (and environmental) objectives of the Chilean climate and energy policy. The international literature indicates that, theoretically, it is possible to achieve energy goals at country level by implementing energy efficiency strategies in the residential sector. However in practice, standards for energy efficiency and carbon emissions have not reached the objectives. This is partly explained, by the fact that there is a gap between the designed and as-built thermal performances of new homes (Gupta et Dantsiou, 2013). This thesis aims to deepen the subject by focusing on the following research question : “How does the quality in the construction process affect the as-built thermal performance of new homes in Chile?”. Therefore, it studies how the quality of implementation, the monitoring and the control of the processes, together with the qualifications of human resources involved in the different aspects of this implementation, are of critical importance to reach the expected designed thermal performance. Based on the hypothesis that the gap between the designed and as-built thermal performances of new homes in Chile is likely to be reduced by using some tools, methodologies or techniques having a direct and predominant influence on the causes of this gap, this thesis first sets a theoretical basis that aims to: Contextualize the reality in which the strategies will be implemented during the construction process to reduce the gap between the designed and as-built thermal performances of new homes in Chile; Define an assessment sys, La consommation d’énergie au Chili est fortement influencée par le secteur résidentiel, avec 20% de la consommation totale du pays (Gobierno de Chile, 2012a). Le gouvernement chilien fixe à 30% le potentiel de réduction de l’énergie utilisée pour le chauffage de ce secteur résidentiel, soit 6% de la consommation énergétique totale du pays (Gobierno de Chile, 2012c). Par conséquent, le secteur résidentiel peut et doit jouer un rôle clé dans la réalisation des objectifs économiques (et environnementaux) de la politique énergétique et climatique chilienne. La littérature internationale montre que, théoriquement, il est possible de réaliser des objectifs énergétiques au niveau d’un pays en mettant en oeuvre des stratégies d’efficacité énergétique dans le secteur résidentiel. Mais, dans la pratique, les normes d’efficacité énergétique et d’émission de carbone n’ont pas atteint les objectifs fixés. Cela s’explique, en partie, par le fait qu’il y a un écart entre la performance thermique prévue lors de la conception et la performance thermique obtenue après la construction (Gupta et Dantsiou, 2013). Cette thèse vise à approfondir ce sujet en se concentrant sur la question de recherche suivante: “Comment la qualité des processus de construction influe-t-elle sur la performance thermique d’une maison au Chili?”. De ce fait, elle étudie dans quelle mesure la qualité de l’exécution, le suivi et le contrôle des processus, conjointement à la qualification des ressources humaines impliquées dans les différents aspects de cette exécution, entre autres, sont d’une importance cruciale pour la garantie des performances thermiques attendues. Sur base de l’hypothèse que l’écart entre la performance thermique prévue lors de la conception d’un logement au Chili et sa performance thermique obtenue après construction est susceptible d’être réduit grâce à quelques outils, méthodologies et techniques qui influent directement et de façon prépondérante sur les causes de cet écart, cette thèse, (BAUR - Art de bâtir et urbanisme) -- UCL, 2015

Les normes d’éclairage public se basent sur l’évaluation quantitative de différents paramètres tels que la luminance, l’éclairement, l’uniformité, l’éblouissement et la répartition latérale de l’éclairage. D’autres paramètres importants pour l’usager devraient également être pris en considération. Une enquête de terrain a été menée sous un éclairage LED et un éclairage HPS afin d'identifier les indicateurs d'un éclairage public de haute qualité conçu pour des piétons. L'enquête compare ces indicateurs aux caractéristiques, énumérées par les participants, des sources LED et des sources HPS. Finalement, l'enquête mesure le sentiment de sécurité, le confort visuel et la perception d'ambiance lumineuse des piétons. Cet article montre que la visibilité proche, le sentiment de sécurité, la luminosité, l'uniformité d'éclairement et le non éblouissement sont les indicateurs les plus importants pour un éclairage public de qualité pour les piétons. En outre, cet article montre également que les caractéristiques d'un éclairage LED, apprécié par des piétons, sont bien corrélées aux indicateurs d'un éclairage public de qualité. Finalement, cette recherche montre que les piétons préfèrent toujours les sources LED aux sources HPS, quel que soit le concept considéré de sentiment de sécurité, de confort visuel ou de perception d'ambiance lumineuse., Street lighting standards are based on quantitative measurements of various parameters such as luminance, illuminance, glare and lateral light distribution. At the moment, we know that subjective criteria are also important for pedestrians in order to achieve high quality street lighting. A field study was conducted under LED light and HPS light in order to identify the indicators of a high quality street lighting designed for pedestrians. The survey compares these indicators to the characteristics, enumerated by the participants, for each LED light or HPS light. Finally, the survey measures the feeling of safety, the visual comfort and the perception of lighting atmosphere for pedestrians. This paper shows that the near visibility, the feeling of safety, the brightness, the illumination uniformity and a non-glare light are cited as the more important indicators of high quality street lighting for pedestrians. Moreover the paper also shows that the characteristics of LED light, appreciated by pedestrians, are well correlated to the indicators of a high quality street lighting. Finally this research shows that pedestrians always prefer LED light to HPS light whatever the concept of feeling of safety, the concept of visual comfort or the perceived luminous atmosphere is concerned.

Une enquête de terrain a été menée afin de déterminer si la distribution spectrale de l'éclairage public influence la capacité des piétons à réaliser différentes tâches visuelles. Cette enquête vise à comparer les performances visuelles des piétons mis sous deux types de sources lumineuses : LED et HPS. Les performances visuelles de 40 personnes âgées entre 17 et 78 ans ont été mesurées au travers de 4 tâches spécifiques: reconnaissance faciale et d'intention, reconnaissance des couleurs, acuité visuelle et détection périphérique. Les résultats montrent que la distribution spectrale des lampes influence les performances visuelles et que l'amplitude de l'effet varie en fonction de la tâche visuelle. En fonction de la tâche, les personnes peuvent accomplir les tâches aussi bien sous les lampes LED que sous les lampes HPS. Pour ce qui est de la détection périphérique, les sources LED permettent d'obtenir de meilleurs résultats que les sources HPS. Cet article confirme que sous des niveaux lumineux mésopiques, où les cônes et les bâtonnets agissent simultanément, les sources LED sont plus efficaces pour les piétons., A field survey was conducted in order to determine whether light spectrum of public lighting influences the ability of pedestrians to perform several visual tasks. This survey aims to compare the visual performance of pedestrian under two kinds of light sources: LED and HPS sources. Visual performance of 40 people aged between 17 and 78 years have been measured through 4 specific tasks: facial and intent recognition, colour recognition, visual acuity and off-axis detection. The results show that the spectral distribution of the lamps influences visual performance and that the magnitude of the effect varies according to the task. Depending on the task, people can perform as well under LED sources than under HPS sources,. But for peripheral tasks, people perform better under LED sources than under HPS sources. This paper confirms that under mesopic light levels, where rods and cones work simultaneously, LED sources are more efficient for pedestrians.

Since these last years, the application of the European Energy Performance Building Directive (EPBD) has led to a higher interest in summer comfort issue. In this context, the design of glazing complexes (glazing and solar shading) is a key issue since it directly influences the thermal and visual perception of interior spaces. Glazing complex determine the view and the opening to the outside, determining solar gains and penetration of natural light, but is also responsible for heat loss and can cause overheating and glare. The choice of an adequate glazing complex should therefore be done considering all of these aspects. This paper presents a free web tool realised within the frame of the PROSOLIS research project. Based on a set of results obtained by the advanced use of BSDF functions for optical properties description of solar shading in specific thermal and daylight simulation software’s (WINDOW 7, EnergyPlus 8, Light-tools 8.0), the PROSOLIS web tool helps to evaluate the impact of the glazing complex choice on both thermal and visual comforts in residential and office buildings. This web tool, dedicated to building designers, proposes a multi-criteria approach for comparing accurately the most current types of glazing complexes. It considers internal and external screen fabrics and venetian blinds, combined with five different types of glazing and informs designers on energy and light performance levels of the selected combinations. From this information, designer should be able to easily choose glazing complexes fitting with their needs.

Many conventional daylighting design tools are limited in that each simulation represents only one time of year and time of day (or a single, theoretical overcast sky condition). Since daylight is so variable – due to the movement of the sun, changing seasons, and diverse weather conditions – one moment is hardly representative of the overall quality of the daylighting design, which is why climate-based, dynamic performance metrics like Daylight Autonomy (DA) and Useful Daylight Illuminance (UDI) are so needed. Going one step further, the annual variation in performance (condensed to a percentage by DA and UDI) is also valuable information, as is the ability to link this data to spatial visualizations and renderings. Trying to realize this combination of analytical needs using existing tools would become an overly time-consuming and tedious process. The challenge is to provide all information necessary to early design stage decision-making in a manageable form, while retaining the continuity of annual data. This paper introduces a climate data simplification method based on a splitting of the year into 56 periods, over which weather conditions are “averaged” and simulated using Perez's ASRCCIE sky model, while information on sun penetration is provided at a greater resolution. The graphical output of the produced data in the form of “Temporal Maps” will be shown to be visually, and even numerically, comparable to reference case maps created using short time step calculations and based on illuminance data generated by Daysim., Boston Society of Architects, Belgian National Foundation for Scientific Research

La Commission Internationale de l’Eclairage émet quelques recommandations au sujet de l’exploitation nocturne de l’éclairage public sans pour autant donner de directives sur la méthode de gradation de l’éclairage. Or, une gestion intelligente de la durée d’allumage et des niveaux de puissance d’éclairage relative aux conditions de trafic est essentielle pour la mise en application d’un éclairage public de qualité et pour la réalisation d’économies d’énergie conséquentes. Cette étude établit un modèle de gestion intelligente de l’éclairage qui combine deux principes de gradation en temps réel de la puissance des lampes : l’échelonnement et la courbe de transfert. Ce modèle permet aux lampes d’adapter leur puissance et la durée d’allumage en fonction de la position et de la vitesse des usagers de la route. Par ailleurs, l’intégration du modèle de vision mésopique permet de réduire la puissance maximale des lampes tout en maintenant une perception photométrique similaire à celle requise en condition de vision photopique. Le modèle de gestion intelligente de l’éclairage en temps réel développé dans cette étude permet de réaliser des économies d’énergie conséquente tout en offrant un niveau de confort visuel et de sécurité optimale aux usagers., The CIE - International Commission on Illumination issues certain recommendations regarding the use of public lighting at night without however giving guidelines on the dimming method. However, intelligent management of the time lighting is switched on and of lighting power levels which reflect traffic conditions are essential for providing high-quality public lighting and achieving significant energy savings. This study sets out an intelligent lighting model which combines two real-time lamp-power dimming principles: spreading and the transfer curve. This model allows the power and time the lamps are lit to be adjusted according to the position and speed of road users. In addition, integrating the mesopic vision model reduces the maximum power of the lamps while maintaining photometric perception that is similar to that required in photopic vision conditions. The intelligent real-time lighting management model developed in this study allows substantial energy savings to be made while providing users with an optimum level of visual comfort and safety.

The evaluation of cooling needs and summer comfort in buildings requires an accurate quantification of solar gains through window systems (glazing and solar shading). However, in dynamic thermal simulation tools, the modelling of shading devices is usually simplified: angular dependency of properties is neglected; shading devices are considered as perfect diffuser; internal reflections between the slats of a venetian blind are neglected or considered only as diffuse. In some cases these simplifications bring significant inaccuracies on the evaluation of solar gains entering the building, and, consequently, on the building thermal behaviour. Bi-directional Scattering Distribution Functions (BSDF) allows a more detailed modelling of materials and systems which enhances the characterisation of the window behavior. The use of these functions appears to be an appropriate way to consider optical angular properties of shading devices in dynamic thermal simulations: it increases the accuracy of results without requiring excessive computation time. This paper shows and discusses the results obtained when using-directional Scattering Distribution Functions in dynamic thermal simulation, for six common configurations of solar shading devices (external screen and venetian blinds of different characteristics), in comparison with those obtained by simplified modelling methods. The Window 7 software was used to generate BSDF data that were then used as input in the EnergyPlus V8 building energy simulation program. Results focus on transmitted solar energy through windows (double low E glazing) and cooling needs of a simple office room for the different solar shading devices. In conclusion, this study shows for several solar shading types (and their characteristics), the importance of considering optical angular properties in dynamic thermal simulation and the accuracy gained obtained by BSDF characterisation.

Virtual renderings are increasingly used in the architectural design process and in lighting quality research to assess the visual appearance of indoor environments. Thanks to imaging technologies continuously in development to improve the "realism" of these images, pictures can nowadays be presented in various ways. Regrettably, to date, few studies assert that such images replicate the visual appearance perceived in actual daylit environments. The present research investigated the perceptual equivalence between actual daylit environments and images. Two types of images – photographs and virtual renderings – were studied as well as four modes of presentation – QuickTime virtual reality (QTVR) panoramas, 2D display, 3D display, and high dynamic range (HDR) display. Eight groups of 40 students viewed four daylit corridors and filled in a questionnaire about the appearance of lighting and space elaborated for the study. The corridors were presented in several ways: a first group of participants visited the actual rooms while the other groups visualized, in a lab context, their reproduction in sketches, photographs or virtual renderings. This research provides some proofs that images can reasonably be used as a surrogate for the real world when studying the appearance of lighting (characterized by the perceived brightness, coloration, contrast, distribution, directivity and glare). On the other hand, the study suggests that images poorly reproduce the appearance of space (pleasantness and enclosedness were studied). As a result of the research, we determined precisely the media to use for studying each dimension characterizing the appearance of lighting and space., Afin d’évaluer les qualités spatiales et lumineuses des espaces qu’ils conçoivent, les architectes ont régulièrement recours aux rendus virtuels. Dans le domaine de la recherche en éclairage également, l’utilisation de ce type d’image est de plus en plus répandue. Pourtant, tandis que de nombreuses technologies de l’image sont développées afin d’encore accroître leur réalisme, peu de travaux ont démontré que celles-ci reproduisent fidèlement les perceptions visuelles ressenties dans les environnements réels. A l'aide d'enquêtes par questionnaire menées auprès de 320 étudiants universitaires, l'équivalence perceptuelle entre des environnements réels éclairés naturellement et leur reproduction en image a été investiguée. Deux types d'images – des photographies et des rendus virtuels Radiance - ont été étudiés ainsi que quatre modes de présentation – l’image 2D traditionnelle, la panoramique QTVR, un écran 3D et un écran HDR en développement (écran permettant d’afficher une large gamme de luminosités). Les résultats obtenus indiquent que la plupart de ces images peuvent être utilisées comme substitut du monde réel lorsqu’on étudie l'apparence de l'éclairage (caractérisée par les dimensions suivantes : luminosité, coloration, contraste, distribution, directivité et éblouissement). Par contre, l'étude révèle que ces images reproduisent peu fidèlement l'apparence de l’espace (les caractères agréable et enclos ont été étudiés). A l’issue de la recherche, les types d’image et les modes de présentation à favoriser pour l’étude de chacune des dimensions caractérisant l’apparence de l’éclairage et de l’espace ont été précisément déterminés., (FSA - Sciences de l'ingénieur) -- UCL, 2013

This study is realized in the frame of a work aiming at evaluating the potential of several presentation modes whose images displayed on 2D, 3D and HDR monitors for studying the perceived visual appearance of daylit spaces. The paper discusses two metrological qualities (sensitivity and validity) of a questionnaire developed in this context. This questionnaire is composed of rating scales, multiple choice questions, and questions based on blank sketches. A first group of forty-three subjects visited actual rooms and responded to the questionnaire. A second group of forty-two participants responded to the same questionnaire without visiting the actual rooms but only on the basis of blank sketches. Results show that multiple choice questions are complementary to rating scales. The comparison of perceptions experienced by the participants having visited the actual rooms to responses given by the control group shows that luminous stimuli influence the way the participants rated the rooms. At last, perceptions experienced by the participants visiting the rooms are in accordance with the objective analysis of the rooms’ luminous conditions realized on the basis of luminance and illuminance measurements.

High dynamic range (HDR) imaging techniques are increasingly used by lighting researchers in building applications to capture luminances in the field of view. This paper deals with the photometric calibration and more particularly with vignetting effect correction, which is one of the steps necessary to ensure reliable data. The vignetting effects of four similar devices (two identical fisheye lenses successively mounted on two identical cameras) were first determined for several apertures. The symmetry, noninfluence of the color of the target, and the similarity of vignetting between the devices were evaluated with root mean square error. Finally, the mapping function of the fisheye lens was checked. This study shows that the vignetting filters determined for one device (a SIGMA 4.5 mm F2.8 fisheye lens mounted on a CANON 40D camera) can be reasonably used by other researchers using similar photographic materials (that is, the same brands and models).

The past decade has seen the construction of many (high-rise) double facade (DF) buildings, for which the glazing is mounted in a pair steel or aluminium frames separated by a large cavity. In many cases, a key aspect of this system is the improved acoustic performance compared with single facades. Therefore, it has become eminent to understand the acoustic properties of DF. It also seemed that a crucial need had arisen to be able to predict the acoustic performances of DF at the tendering stage (as is already possible from a thermal point of view). In the tendering stage of a project the project managers are dealing with large amounts (typically more than 10.000 m²) of glazing to be used in the facade. The choice of a particular type of glazing has an important impact on the total cost of the building. In the years before many decisions led to over-dimensioning of the glass types due to a lack of knowledge, which obviously led to higher building costs, leaving economic optimisation out of the loop. This crucial factor led to the research on the acoustic properties of DF systems, which consist of more than two glass panes, in contrast to the usually referenced double systems, which only have two (glass) panes. The goals for this research were set: a clear and detailed picture on the acoustic behaviour of DF and the creation of an acoustic calculation model to predict the facade insulation of DF with sufficient accuracy and with limited computation time, which is crucial at the tendering stage of a building project. This model is a semi-empiric hybrid model (SEHM) which consists of existing adapted and new models based on statistical energy analysis (SEA) and semi-empiric models. The SEHM has been validated by comparison with a large amount of experimental results and reveals to be very encouraging, showing high accuracy over the investigated frequency bands and minimal computation time., (FSA 3) -- UCL, 2012

Overheating appears as a recurrent problem in apartments of the real estate market of Santiago de Chile, since their architectural design frequently does not incorporate passive cooling techniques and some occupants may not be completely aware of their impact on the thermal comfort. This situation is encouraged by a Thermal Regulation that allows extensive single glazing surfaces in the building envelope of the apartments in Santiago and that does not propose any criteria or recommendations for limiting the risk of overheating during the cooling period. In addition to this, the real estate market has practically not been studied in terms of the impact on the thermal comfort and could not be considered as correctly represented by the building typologies designed in light of the Thermal Regulation. To deal with this entire scenario, we proposed the application of passive cooling strategies with the aim of obtaining adequate conditions of summer comfort and avoiding the use of air conditioning in apartments of the real estate market of Santiago. In this sense, this paper establishes the definition of apartment typologies through a multidimensional approach to market disaggregation, a sensitivity analysis with the aim of assessing the possibilities to reduce the risk of overheating by means of passive cooling techniques and two questionnaire surveys related to occupant behaviour with respect to natural ventilation and the interest and to the willingness to purchase solar protection devices. The results obtained suggest that the best performance in terms of summer comfort can be obtained from the combination of diverse variables that would be significant in respect to the reduction of the risk of overheating. In this sense, the presence of solar protection devices and night ventilation constitute very significant input parameters, especially with respect to living rooms and bedrooms, respectively. However, the favourable results obtained for night ventilation should not, (ARCH 3) -- UCL, 2012

Daylighting has taken on an important role in sustainable architecture, since it has a major impact on the energy efficiency of a building allowing, first, to reduce the load on artificial lighting and, at the same time, to reduce the internal gains of the buildings. It is important to point out that it also has a positive effect on human health, wellbeing, visual comfort and performance. In schools, it has been proven that daylighting plays an important role in the learning process and the behavior of the students. The objective of this thesis is to define daylight criteria for the development of daylighting design strategies for classrooms, with the purpose of ensuring the visual comfort of the students. The specific objectives are: first, defining the standards for the application of the criteria, based on a dynamic daylight metric considering weather data, the different types of skies, seasons of the year and times of the day; second, conceiving, verifying and demonstrating the effectiveness of the developed strategies; and, finally, creating a consultation tool, that serves as a reference for classroom design, allowing for the understanding of light distribution and visual comfort conditions of the students, in a fast and easy way. A new methodology for the conception of daylighting design strategies of classrooms was obtained, based on four criteria related to visual comfort; these are: the amount of daylighting, daylighting uniformity, presence of glare risk in the field of view and sunlight penetration in the classrooms. Given the dynamics and variability of the light, this is evaluated through new dynamic simulation methods, which take into account the amount of daily and seasonal variations of daylight, combined with weather data. The evaluation of these criteria, in classrooms, was determined by RADIANCE simulation, where the values are plotted in the temporal and spatial maps in order to evaluate daylight and visual comfort throughout the year. For these, (ARCH 3) -- UCL, 2011

The 27th PLEA conference PLEA2011 - Architecture and Sustainable Development marks the 30th anniversary of PLEA. The topics of the conference tackle a broad range well beyond the subject of energy. Following from the last PLEA conference that was held in Quebec in 2009, we want this celebratory PLEA 2011 in Louvain-la-Neuve to provide a special meeting ground for architects, engineers and researchers to debate the theme of sustainable architecture and the different aspects of sustainable development that range from the scale of the city to those of materials and components. This book of Proceedings presents the latest thinking and research in the rapidly evolving world of architecture and sustainable development through 255 papers which were selected out of more than 750 abstracts that were proposed by authors coming from over 60 countries.

This paper presents the principles and methods for the integration of natural light and comfort criteria into architectural classroom design. The aim is to create the basis for incorporating these principles in the design of Chilean classrooms, to improve daylighting design in order to minimize glare and achieve more uniform daylighting levels throughout the school year. Firstly, the fundamental principles that directly affect design are defined. Secondly, the evaluation methods and measurements for those principles are described. Finally, we give some preliminary results for the various typologies and daylighting strategies. The research context is the city of Concepción, in Chile. Virtual models of classrooms were evaluated with the Radiance software. The annual assessment of the light performance of each classroom type was made for each of the four cardinal directions (north, south, east and west) and under the four sky types defined by CIE during the school year, March to December. The methods used and the formats for the representation of results are defined for each design principle. This paper proposes a new methodology, which could be implemented in future classroom design and also could be employed to evaluate existing classrooms.