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This paper reports on two experiments conducted in the same office laboratory. As part of a larger experiment, 58 participants worked for a day under one of two lighting designs. The first design used ceiling-recessed parabolic luminaires only; the second design employed the same parabolic ambient lighting, with the addition of an angle-arm task light. Participants had no control over the lighting until the afternoon, when they were offered dimming control over the ambient parabolic lighting; participants with task lighting were also permitted to move the arm location. During the day participants performed a variety of simulated office tasks, as well as completing a number of questionnaires on mood, satisfaction, and discomfort. There was no main effect of lighting design on questionnaire outcomes, however, task lighting was associated with performance improvements on some tasks. Interestingly, provision of a task light did not lower participants' preferred ambient light output. The second experiment, with 31 participants, followed up on this final point. Again, ambient lighting was provided by ceiling-recessed, parabolic luminaires, and participants were provided with a task light. For two task light types (angle-arm and luminous shade) at three different levels of output (0%, 50%, and 95%), participants used a dimmer to select their preferred level of ambient lighting. Increasing task lighting did reduce chosen ambient light output, but the reduction in lighting power was small, and only about the same as the power drawn by the task light. Results suggested that participants did not dim ambient lighting further because they preferred to maintain illumination on non-task surfaces, and to avoid extreme luminance ratios.

Also available in English: Tubular daylighting devices an alternative to skylights

Aussi disponible en français: Les lanterneaux tubulaires d'éclairage naturel : une solution de rechange aux lanterneaux classiques

This was a naturally-occurring field experiment, comparing employee responses to recessed parabolic-louvered luminaires, and workstation-specific individually-controllable suspended direct/indirect luminaires, with some variation in furnishings and surface reflectances. All occupants of three buildings were invited to complete an online questionnaire on three occasions during the study. Each time, the questionnaire included questions and tasks to assess satisfaction with lighting, room appearance judgements, mood, environmental satisfaction, job satisfaction, organizational commitment, intent to turnover, persistence, and well-being. Each measurement wave included a site visit by the research team, during which the physical conditions in selected locations were measured. The results showed that 1. Workstation-specific lighting with individual control is the higher-quality lighting solution. 2. Room surface reflectances influence lighting quality. 3. Luminous conditions matter to organizational productivity. Luminous conditions (rated on a scale from parabolic/low reflectance to workstation-specific-control/low reflectance to workstation-specific-control/high reflectance) predicted lighting appraisals, and these in turn indirectly related to reduced health problems and to reduced intent to turnover. Previous NRC-IRC research had found that this lighting solution saved up to 69% of the energy used by the original parabolic-louvered luminaire design. The evidence that these luminaires also deliver a higher-quality work environment, and furthermore that this environment is associated with fewer health problems and better employee retention, makes this lighting solution an excellent choice for individuals, their employers, and the environment.

We conducted a field study in a deep-plan office building with cubicle accommodation and large windows. Workstation-specific suspended direct-indirect (WSDI-C) luminaires with occupancy sensors, daylight-linked dimming, and individual controls were located centrally in each workstation provided lighting over most of the floor area. Part of one floor featured a conventional ceiling-recessed parabolic-louvered lighting system with zonal on-off switching. This report concerns the occupants' evaluations of the office lighting as reported in three questionnaire waves. Results showed that WSDI-C system was associated with a superior indoor environment in comparison to the conventional system.

This paper reports a field investigation in to the behavioural effects of an energy-saving lighting retrofit. The results show that workstation-specific direct-indirect lighting with individual control is perceived as being more comfortable than recessed parabolic-louvered luminaires. Offices lit with the new lighting were more likely to be perceived as having better lighting than other similar offices. These effects have been previously associated with better outcomes related to organizational productivity. The pattern of results from several studies shows that good-quality lighting can deliver individual, organizational, and environmental benefits.

Aussi disponible en français: Faits saillants: Écologique ce bâtiment?

Also available in English: Highlights - How green is your building?

Exterior window shading devices have the potential to reduce solar overheating in summer and heat losses in winter, and to improve the thermal comfort of occupants compared to interior shadings. This paper reports on the first winter of field measurements intended to develop guidelines for effective exterior, mid-pane (inside the window) and interior window shading devices. Exterior insulating rollshutters were installed on the windows of a typical, four-bedroom, two-storey detached house and their performance was compared to interior blinds installed in an identical neighbouring house. In both houses, the shading devices were open during daytime hours admit solar heat in and were closed during night-time to reduce window heat loss., IBPSA-Canada eSim Conference: 20 May 2008, Quebec City

This paper presents a comparison study between the simulations of SkyVision and measurements made in a scale model. SkyVision is a computer tool to calculate the overall optical characteristics, indoor daylight availability and energy saving potential of projecting and tubular skylights. The measurements included the overall visible transmittance and indoor daylight illuminance of the skylight. A rectangular wooden box was used as a scale model of a simple commercial building. The top surface of the box was fitted with a curbed opening to accommodate the skylights to be tested. Seven skylight shapes were tested: two circular dome models, one with clear and one with white acrylic glazing; two rectangular bubble dome models, one with clear and one with white acrylic glazing; a clear acrylic hexagonal pyramid model; a clear polycarbonate barrel vault model; and a tubular skylight model. The measurements were conducted for a whole day period, thereby covering different sky conditions: overcast, partly cloudy and clear sunny skies. SkyVision's simulations for the skylight transmittance compared reasonably well with the actual measurements, except for the hexagonal pyramidal skylight. The hexagonal pyramid surface exhibited some lens effects around the surface vertices, which were not possible to model in SkyVision. As for the skylight indoor illuminance comparison, the SkyVision's simulations were in good agreement with the actual measurements for all occurrences of sky conditions., Also presented at the ASHRAE Summer Meeting, June 24-28, 2006, Quebec City

Research results suggest that health in industrialized countries might be improved if people received a greater quantity of light at the eye. Achieving this using current architectural and lighting practices poses several challenges for research and for application. This paper explores issues of measurement and photometry using data from a dedicated daylighting facility., CIE Symposium '04 - Light and Health: Non-Visual Effects: 30 September 2004, Vienna, Austria

This experiment was conducted in a mock-up office-space laboratory. One hundred and eighteen participants worked for a single day under one of four lighting designs. They had no control over the lighting until the latter half of the afternoon, when all participants were offered some form of individual dimming lighting control. During the working day participants performed a variety of simulated office tasks, as well as completing a number of questionnaires on topics such as mood, satisfaction, and discomfort.Results related to questionnaire outcomes were consistent and convincing. After lighting control was offered there were significant improvements in mood, room appraisal, lighting satisfaction, glare dissatisfaction, environmental satisfaction, satisfaction with performance, self-assessed productivity, and visual discomfort. Further, our results suggest that it is not control in itself that is important, but exercising control to achieve preferred conditions. Participants who made the biggest changes to lighting conditions after they were given control tended to register the biggest improvements in mood, satisfaction and discomfort outcomes; those who made little change registered no improvements in outcomes. Task performance results were more equivocal. On many tasks, performance did significantly improve after control was introduced, but we attribute these improvements primarily to known practice effects. We recommend field studies over the longer term to test whether mood and satisfaction effects persist, and whether performance effects emerge., IESNA Annual Conference: 26 July 2004, Tampa, Florida

IRC has released the final version of its SkyVision software for predicting skylight performance afterextensive validation testing on the beta version released last year. Skylight designers, skylightmanufacturers, building designers, fenestration rating councils, architects and educators can use the toolto predict the daylighting performance and energy saving potential of conventional and tubular skylights.This report outlines the test methodology to measure the skylight performance, and presents thecomparison study between the software's predictions and the actual measurements. This report alsoincludes a comparison with the results of the California PIER (Public Interest Energy Research) programfor the effective transmittance of skylight and well combinations. The results of the PIER programcovered additional skylight settings, and provided valuable benchmarks not only for the effectivetransmittance, but also for the thermal transmittance (U-value) and the solar heat gain coefficient ofprojecting skylights., L'IRC a publié la version définitive de son logiciel SkyVision de prédiction des performances des lanterneaux après avoir soumis la version bêta parue l'an dernier à des excès de validation exhaustifs. Les concepteurs et les fabricants de lanterneaux, les concepteurs de bâtiments, les conseils d'évaluation de fenestrages, les architectes et les éducateurs peuvent utiliser l'outil pour prédire les performances en matière d'éclairage naturel et le potentiel de conservation d'énergie des lanterneaux de forme classique ou tubulaire. Le rapport donne les grandes lignes de la méthode d'essai utilisée pour mesurer les performances des lanterneaux et présente l'étude de comparaison entre les prédictions du logiciel et les mesures réelles. Il inclut également la comparaison avec les résultats du programme PIER (Public Interest Energy Research) de la Californie relatif à la transmittance effective de combinaisons de lanterneaux et de puits de lumière. Les résultats du programme PIER couvraient des environnements de lanterneaux supplémentaires et offraient des repères précieux non seulement pour la transmittance effective, mais aussi pour la transmittance thermique (valeur U) et le coefficient d'apport par rayonnement solaire des lanterneaux en saillie.

This experiment was conducted in a mock-up office space laboratory. 118 participants worked for a single day under one of four lighting designs (Figure A). They had no control over the lighting until the second half of the afternoon, when all participants were offered some form of individual dimming control. During this working day participants completed a variety of simulated office tasks and questionnaires related to mood, satisfaction, and discomfort. An earlier report [Newsham et al., 2003] described initial data analysis of questionnaire outcomes and photometric data. In this report we supplement this information with analysis of the task performance data and more detailed photometric data. For completeness, this Executive Summary will summarize the findings of the experiment as a whole., Cette expérience a été menée dans un modèle en vraie grandeur de surface de bureaux dans un laboratoire. Cent dix-huit (118) participants ont travaillé pendant une seule journée sous un de quatre éclairages différents (Figure A). Ils n'avaient aucun moyen de commander l'éclairage jusqu'à la seconde moitié de l'après-midi, lorsque tous les participants se sont vu offrir une forme quelconque de commande de l'intensité de l'éclairage. Au cours de la journée de travail, les participants ont exécuté diverses tâches de bureau simulées et rempli des questionnaires se rapportant à l'humeur, à la satisfaction et à la gêne. Dans un rapport antérieur [Newsham et coll., 2003] on décrivait la première analyse des résultats des questionnaires et des données photométriques. Dans le présent rapport, on ajoute à cette information l'analyse des données relatives à l'exécution des tâches et des données photométriques plus détaillées. Pour que l'information soit complète, on trouvera dans le présent résumé le sommaire des conclusions de l'expérience dans son ensemble.

This experiment was conducted in a mock-up office space in a laboratory. 118 participants worked for a single day under one of four lighting designs. They had no control over the lighting until the last half of the afternoon, when all participants were offered some form of individual dimming lighting control. During this working day they completed a variety of simulated office tasks (not analysed in this report, but to be reported later), as well as completing a number of questionnaires. The experiment was designed to address several research questions with direct relevance to office lighting practice. We looked at preferences for particular lighting designs, particularly designs that provide higher levels of vertical illuminance. We were also interested in whether local/task lighting sources reduced the demand for ambient lighting. We also examined whether providing individual dimming control over luminaires was beneficial., Cette expérience a été menée sur un modèle en vraie grandeur de surface de bureaux dans un laboratoire. Cent dix-huit (118) participants ont travaillé pendant une seule journée sous un de quatre éclairages différents. Ils n'avaient aucun moyen de commander l'éclairage jusqu'à la seconde moitié de l'après-midi, lorsque tous les participants se sont vu offrir une forme quelconque de commande de l'intensité de l'éclairage. Au cours de la journée de travail, les participants ont exécuté diverses tâches de bureau simulées (non analysées dans le présent rapport, mais qui doivent faire l'objet d'une communication ultérieure), en plus de remplir un certain nombre de questionnaires. L'expérience visait à aborder plusieurs questions de recherche directement pertinentes à la pratique en matière d'éclairage des locaux à bureaux. On a jeté un coup d'oeil aux préférences pour des modèles d'éclairage particuliers, surtout ceux qui offrent des niveaux plus élevés d'éclairement lumineux vertical. On était également intéressé à savoir si les sources d'éclairage local ou de tâche réduisaient la demande pour de l'éclairage ambiant. On a aussi examiné la question de savoir s'il était avantageux de permettre à chaque personne de commander l'intensité des appareils d'éclairage.

Current office lighting recommendations stress the importance of vertical surface illumination over horizontal desktop illumination for VDT work, where the occupant is primarily in a 'heads up' position. We investigated this recommendation by creating two very different lighting conditions in two workstations in a mock-up open-plan office space. One workstation was provided with conventional, dimmable ceiling-recessed parabolic fixtures. The other, adjacent, workstation featured an innovative, dimmable, 'partition washer' system designed to preferentially light the vertical surfaces in the occupant's field of view; this was supplemented by a fixed 150 lx on the desktop from overhead. Participants (lighting experts) were assigned to one of the workstations and spent around 7 minutes reading and evaluating an on-screen article and a summary of the article, and completing an on-screen questionnaire on satisfaction with the lighting. This was done under one of four fixed initial lighting conditions. The participants then set the lighting to their own preference using on-screen dimmers, and repeated the task and questionnaire.Participants then switched workstations and repeated the procedure under the other lighting condition. Results showed that there was no significant difference in satisfaction between lighting conditions, although the partition washer condition required significantly less power. Participants were more satisfied with the lighting after control independent of lighting conditions, as expected. Further, derivation of preferred surface illuminances suggests that supplementary partition illuminance, beyond that which is provided by ceiling-recessed parabolics, is desirable., Proceedings of the IESNA Annual Conference: 04 August 2002, Salt Lake City

Illuminating engineers, lighting designers and others have long debated the importance of providing an artificial light source that mimics the characteristics of natural light. Several products are available that purport to provide more natural light, of which retrofit plastic filters are one. Product testimonials praising these products abound, but there is little empirical data concerning their effects on the visual environment. This paper reports two experiments concerning this issue, the first being a test of the hypothesis that selected retrofit magenta filters improve skin appearance in comparison to other common lighting sources or a placebo condition. The second experiment tested the hypothesis that selected retrofit magenta filters improve short-term visual performance, compared to other common lighting sources or a placebo condition. The results show that the selected filters improved skin appearance relative to unfiltered fluorescent lamps. There were no differences between preferences for skin appearance under comparable magenta filters from two different manufacturers. In general, light sources relatively richer in red than green were preferred. There were no effects of light source spectral composition on short-term visual performance., Was presented at the Illuminating Engineering Society of North America Conference in Ottawa in 2001, pp. 507-528.