31.12.05 - Innovative bidirectional video-goniophotometer for advanced fenestration systems. Thesis EPFL, n° 2941 (2004). Dir.: Prof. J.-L. Scartezzini.

Dans sa thèse, Dr Marilyne Andersen se penche sur un des problèmes très importants de la construction de bâtiments commerciaux et domestiques : la lumière. Elle démontre non seulement l'intérêt scientifique de ce domaine mais ses apports directs au bien-être des utilisateurs et ses importantes liaisons avec l'économie. La lauréate prouve ainsi sa grande motivation à la cause du développement durable dans une spécialité, l'habitat, où la consommation énergétique et la mobilité correspondent au tiers des contraintes imposées à l'environnement.

Innovative bidirectional video-goniophotometer for advanced fenestration systems

In the present context of increasing needs for sustainability and energy savings, reducing the environmental impact of buildings positions itself as a priority.
As a consequence, the control of daylight and solar radiation through fenestration systems has received a growing attention both in research and practice for the past two decades. Advanced strategies have been developed at different levels to improve energy efficiency by minimizing both electric lighting and heating or cooling loads of buildings. At the same time, enhancing the contribution of daylight was proved to improve greatly the visual comfort and indoors environment of the users.

To increase both the use and control of daylight within buildings, an always larger variety of innovative daylighting systems appears on the market, including novel solar blinds, new glazing or coating materials and daylight-redirecting devices.

Within the framework of this PhD thesis, an original, leading-edge and time-efficient measurement device was developed for their detailed investigation. It successfully introduced the following innovations compared to similar devices:

the time needed to investigate the emerging light distribution for a given incidence was reduced from several hours to a few minutes, making such data - at last - accessible and affordable;
the detection principle being based on a combination of digital imaging techniques and projection on a screen, the light distribution was detected in a continuous way, thus avoiding the risk of missing discontinuities (peaks, troughs) and the necessity for data interpolation;
the measurements were thoroughly validated, using different and original approaches, which led to an error of only 10% despite the complexity of this kind of photometric quantities.