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On the fifth floor of the Braembuilding – the main building of the VUB – is a complete new lighting design installed. The renovated lighting installation has been performed by masterstudent Victorien Desmars of Lighting Research at the VUB. Internally, the project was handled by Daniel (Dany) Stassen. Professor Valéry Ann Jacobs of the Lighting Research group LUXETEC, and supervisor of Victorien, explains what good lighting is. “The first, and foremost, reason to plan lighting is to provide the right lighting at the right time at the right place, without causing visual hindrance.”
“With the upcoming event on the renovation of the Braembuilding in mind on the 11th of September, we would like to draw your attention to a relighting that already took place. Indeed, those of you that have been at the secretariat of our Rector Caroline Pauwels lately, will have noticed that the lighting installation has already been renovated. And most importantly, this relighting was worked out by one of our own students, Victorien Desmars, under supervision of his promotors Dr. Charlotte Goovaerts and Prof. Valéry Ann Jacobs. In the BRUFACE master programs in civil engineering and architecture, students can follow two courses on lighting: artificial lighting and daylighting in buildings. They learn to design by doing so, and VUB is more than happy to provide them with some concrete projects to work on: sports halls, parkings, lecture halls… all these have been redesigned by our students. For the students, this is most interesting, as they also learn to work together: not only with their classmates, but also with the infrastructure department of VUB—in this case with Daniel Stassen, who coordinated the project—and with lighting manufacturers, for this project with ERCO, who teamed-up with the Belgian designer Vincent Van Duysen to design this modular lighting solution.
“So, let’s turn our attention to what constitutes good lighting. And what do we need a light plan for? We could definitely kick in some open doors, and talk about energy savings and carbon footprints, but quite a lot of ink has already been devoted to that matter (deservedly), so let’s try to shed some light on other aspects first. The first, and foremost, reason to plan lighting is to provide the right lighting at the right time at the right place, without causing visual hindrance. And we should strive to do so in the most sustainable way. Now that is easier said than done, and (luckily) more than one solutions exists. In order to qualify as a good lighting solution, some metrics were put forward to promote visual comfort: average illuminance, uniformity, glare, color, … For example, in the secretariat of our Rector, which constitutes an office space where reading and typing are important, the illuminance on the desks was designed to reach a value above 500lx, and by carefully distributing the light sources across the ceiling, a high uniformity was met on the desk. The chosen light solution combines direct and indirect lighting: the indirect lighting towards the ceiling brightens the whole room in a diffuse manner, in addition to the natural lighting, while the direct lighting provides task lighting to the desks. Moreover, spotlights were placed to highlight some artwork. For sculptures, a spotlight shapes the object and gives it a 3D structure that highlights it from its environment, while for paintings or images, a “wallwasher” is used to evenly illuminate the content. Because illuminance decreases with (the square of the) distance, such wallwasher has an asymmetrical light distribution that emits less light to the upper part of the painting (that is closer to the light source,) and more light towards the lower part of the painting (that are further away from the light source) thus promoting an even illuminance on the painting. Another important factor is to reduce glare, as this causes visual hindrance. Both the artificial lighting and daylighting may contribute to a glare-sensation. To prevent glare from artificial lighting, we chose to work with light solutions that are diffuse, while interior venetian blinds or roller blinds are often used to prevent glare due to daylighting. Also veiling glare can occur, which is the unwanted reflection of a light source (a luminaire or a window) on a painting or photograph. To minimize this type of glare, one should carefully consider the location of the light source with respect to the painting. Imagine that the painting is a mirror and that light, that is incident on it, is reflected in the same angle as the angle of incidence you’re your eye captures the reflected light, meaning that the reflected light is coming towards you directly. In that case, you can be blinded. And although the reflection of a painting is different than a mirror (it is less directional), it does have a specular component that will reflect some unwanted light towards the observer. So, the best way to prevent this from happening, is to prevent light to go in that direction from the start by placing it in a different direction. Further, we have chosen a light source with a neutral color temperature and a high color-rendering index (CRI). A lower color temperature is often associated with warmth and coziness, while higher color temperatures are perceived to be colder. As this office has quite some daylight penetration, and daylight varies from warm to cold and back to warm during the day, we have chosen for a neutral color temperature. A high color rendering on the other hand assures that colors are well represented and can be discriminated. Finally, and coming back a bit to the idea of sustainability, or at least modularity, the proposed solution is flexible: all light sources can easily be attached to or removed from the voltage rail that is mounted to the ceiling. So, whenever the layout of the office is changed, it is merely a question of moving the individual luminaires to the desired position.
“As we hope to welcome quite a few students to our courses in (day)lighting in the next academic years, we would like to fast-forward to some future projects on our campuses. The VUB could host several living labs where we can implement and test the lighting of the future. Thanks to a tremendous effort from our colleagues of Infrastructure, Strategie en beleidsvorming, Preventie en Milieu and the Faculty of Engineering, VUB applied and received (!) funding from the Flemish Climate Fund to relight several sites on campus by the end of 2019 for a total value of nearly 1 million euro (of which half is subsidized by the Flemish Climate Fund). Smart lighting solutions, integrating sensors and camera systems will increase our perception of safety on campus, and will provide efficient and effective lighting. Hopefully we can again count on our students to develop many of these projects on campus, so that we can come back to you with a most-interesting follow-up!