"Sunlight as a source of indoor illumination, studies from high latitudes" by Barbara Matusiak
Barbara Szybinska Matusiak
Project manager & Partner
Lecture from the 7th VELUX Daylight Symposium “Healthy & climate-friendly architecture– from knowledge to practice” that took place in Berlin on 3-4 May 2017. For more information visit http://thedaylightsite.com
“Sunlight as a source of indoor illumination, studies from high latitudes” by Barbara Matusiak. The most profound paradox in the daylighting of buildings is related to the utilization of direct sunlight. Huge luminous intensity creates great potential for its utilization as a light source. However, in common practice sunlight is mostly kept away by various forms of sun shading devices. At most work places electric light is used for lighting even during sunny days. The last twenty years of research provides us systematically with new evidences about beneficial and therapeutic effects of sunlight in architectural spaces.
To create buildings that promote health, we need to find better ways to fully exploit sunlight’s benefits. We need to optimize its penetration and find smarter ways to distribute it in interiors so it certainly does not create visual or thermal discomfort. The task is especially challenging in regions with high frequency of overcast sky, where the utilization of sunlight should not be done at the expense of effective utilization of diffused light from the sky. The paper discusses new solutions which are best suitable for regions located at high latitudes and refers to both apartment and office buildings.
The solutions for apartment buildings are exemplified by a detached one-family house in Trondheim were the room shape, roof sloping, windows, skylight design and mirrors in the skylight well are combined for an exceptional result which is even more accentuated by very original coloration of the walls. The intensity of sunlight is reduced by distributing the light over the ceiling/ walls in a way that ensures that the sunlight never falls down on occupants. The solutions for offices are exemplified by two buildings at the university campus at NTNU in Trondheim. In the first one workplaces for students of architecture are located. The demands for visual comfort are high as students work here with analog drawings and models as well as with computer tasks.
The combination of windows and skylights turned out to function very well especially after refurbishment when the old plastic skylights were replaced by clear glazing. Additionally, specular material was used in skylight wells and specially developed sunlight scattering transparent acrylic plates were positioned under the skylights. During the development of the scattering plates, the care has been taken to keep as high perforation degree as possible to maximize penetration of diffused light from the sky in periods without sun. The scattering plates distribute sunlight evenly in the room creating also huge potential for energy savings for lighting as the illuminance on worktables is more than doubled in all daylight conditions.
The project has been partly described in the book “Energy Efficient Buildings”, ISBN 978-953-51- 4877-7, 12.2016. A different design of the sunlight scattering acrylic plates has been developed for a high rise office building. The rooms have rather high south oriented windows. The new sunlight scattering panels are positioned in the upper part of the window keeping possibility for view and control of glare (white venetian blinds) in the lower part. As the sunlight scattering panels are not shaded, they will ensure adequate and comfortable illumination of the room exclusively with sunlight and therefore prevent usage of electric light during sunshine time. The solutions were created over the last few years by the Light & Colour Group at NTNU, Norway.
Barbara Szybinska Matusiak has seven years’ experience in architectural practice. During this period she won several closed architectural competitions in Norway. She joined the Faculty of Architecture at NTNU in 1994 as a research fellow. Her doctoral project, supervised by Professor Øyvind Aschehoug, was devoted to daylighting in linear atrium buildings at high latitudes (finished 1998). Since then she has been involved in many Norwegian and international scientific projects dealing with daylighting and artificial lighting in architecture, e.g. project manager of the “Visual environment in apartment buildings”, partner in the “Translucent Façade” project and a partner/member of SYN-TES, the Nordic network. Nowadays she leads two RCN projects: “DayLighting” and “HOME”. She is also strongly involved in the activities of the international organizations: CIE, AIC and IEA and is the Norwegian representative in the CEN group working with the proposal of a new European standard for daylighting in buildings. She designed the artificial sky and artificial sun for the Daylight laboratory and the newest version of the full-scale room laboratory ROMLAB. Her teaching activities (master courses) are devoted to daylight, artificial light and colour in architecture.