chapter 6: Optimising Daylight in South Africa: A Case Study
Conclusions
Previous generations of architects had understood the window opening as a discrete source from which light flowed. They had channeled it, by interior light reflection and inter-reflection, to produce adequate illumination, and in this context to obtain a distinctive modeling of the interior and the objects in the interior. Paintings of the seventeenth century Dutch school, exemplified by Vermeer and de Hooch, exploited these effects (Button, 1993). Building designers are now required to consider and optimize natural daylight design. This requires an in depth knowledge of solar movement and angles and takes effort and care as it strongly influences the energy consumption of the building and the general comfort of the occupants (Gabriël, 2009). Many solutions and tools exist for performing natural daylight penetration analyses. Ecotect is a useful tool for less thorough daylight analyses for designers with little knowledge of detailed daylight design. This software quickly gives fast interpretable information for early design phases. However, when energy savings estimation due to daylight is the goal, Radiance should be used for more reliable results, because it supports ray-tracing techniques (Gabriël, 2009).
References
Button, D., Pye, B. 1993. Glass in Building. Butterworth Architecture. CIE DS 011.2/E:2002. 2002. Spatial distribution of daylight - CIE standard general sky. Commission Internationale de l’Eclairage. Conradie, D.C.U. 2011. Maximising the Sun. In The Green Building Handbook, South Africa, Volume 3. Alive2green, pp. 147-159. Conradie, D.C.U. 2012. SA Climate Zones and Weather Files. In The Green Building Handbook, South Africa, Volume 4. Alive2green. Gabriël, S. 2009. Integration of daylight and visual comfort by the use of an architectural design methodology for early design stages. In proceedings of the 3rd CIB International Conference on Smart and Sustainable Built Environments, June 15-19, 2009, Delft, The Netherlands. Holm, D. 1996. Manual for Energy Conscious Design. Department of Minerals and Energy Directorate Energy for Development. Hughes, G. 2006. The Headquarters Building for the New Tork Times. In proceedings of second national conference of IBPSA-USA (Simbuild2006, August 2-4, 2006, Cambridge, Massuchusetts. International Energy Agency (IEA). 2000. Daylight in Buildings. A Source book on daylighting systems and components. A report of IEA SHC Task 21/ ECBCS Annex 29. NOAA. 2011. Solar Position Calculator. National Oceanic and Atmospheric Administration (NOAA). http://www.srrb.noaa.gov/highlights/sunrise/azel.html . Accessed 7 November 2011. Osburn, L. 2010. Lighting. In The Green Building Handbook, South Africa, Volume 2. Alive2green. Pp. 297-306. Rasmussen, S. 1964. Experiencing Architecture. Chapman and Hall, London. Rubel, F., Kottek, M. 2010. Observed and projected climate shifts 1901 – 2100 depicted by world maps of the Köppen-Geiger climate classification. In Meteorologische Zeitschrift, Vol 19, No. 2, 135-141. SANS 10114-1. 2005. South African National Standard. Interior lighting Part 1: Artificial lighting of interiors. SABS Standards Division. SANS 204-1. 2008. South African National Standard. Energy efficiency in buildings, Part 1: General requirements. SABS Standards Division. SANS 204-2. 2008. South African National Standard. Energy efficiency in buildings, Part 2: The application of the energy efficiency requirements for buildings with natural environmental control. SABS Standards Division. UNEP. 2009. Greenhouse Gas Emission Baselines and Reduction Potentials from Buildings in South Africa. United Nations Environment Programme – Sustainable Buildings & Climate Initiative. Wikipedia. 2011. Daylight factor. http://en.wikipedia.org/wiki/Daylight_factor. Accessed 10 November 2011.
(Footnotes)
1 Dalle de verre is a French term meaning slabs of glass. Artists using this medium typically use 203 x 254 x 19 coloured slabs of glass. The glass is set in fine reinforced concrete or resin. This is an interesting modern alternative for stained glass. 2 Anidolic lighting systems use non-imaging optical components such as parabolic or elliptical mirrors to capture exterior sunlight and direct it deeply into rooms while also scattering rays to avoid glare.
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