A comparison of luminous efficacy models based on data from Vienna, Austria
- First Online:
- 145 Downloads
To support building design in view of daylight quality, computational (simulation) tools can provide effective support. To perform detailed daylight analysis via simulation, appropriate sky models are needed. In the past, various sky luminance distribution models have been developed. Such models, however, require illuminance data for the relevant location. As measured external illuminance levels are not available for many locations, the more widely available irradiance measurements can be translated, using proper luminance efficacy functions, into illuminance values. The present paper compares five global luminous efficacy models based on a database of measured illuminance and irradiance data from Vienna, Austria. These models typically involve mathematical formulations with multiple coefficients, whose values are derived for a specific location. The results suggest that these models performed rather poorly, once tested against Vienna data. However, the models’ performance improved significantly, once the respective coefficients were modified (calibrated) using the Viennese database.
Keywordsdaylight illuminance irradiance global luminous efficacy simulation
Unable to display preview. Download preview PDF.
- Dervishi S, Mahdavi A (2010). A simple method for the derivation of illuminance values from radiance data. In: Proceedings of BauSim 2010-Building Performance Simulation in a Changing Environment (pp. 495–498), Vienna University of Technology, Austria.Google Scholar
- Aydinli S, Krochman J (1983). Data on daylight and solar radiation. Draft for CIE TC, 4,2.Google Scholar
- Mahdavi A, Dervishi S (2010). An empirically-based global luminous efficacy model for Vienna, Austria. Internal Report. Department of Building Physics and Building Ecology. Vienna University of Technology, Austria, 2010.Google Scholar
- MATLAB (2010). MATLAB Release 2010a, The MathWorks, Inc., http://www.mathworks.com.
- Mahdavi A, Dervishi S, Spasojevic B (2006). Computational derivation of incident irradiance on building facades based on measured global horizontal irradiance data. In: Koenigsdorff R, van Treeck C (eds), Energieeffizienz Gebäuden und Behaglichkeit in Räumen, BauSIM2006 (IBPSA) (pp. 135–137). München: Eigenverlag TU München.Google Scholar
- Zavodnikova K (2010). Derivation of diffuse irradiance based on measured global irradiance data. MSc thesis, Vienna University of Technology, Vienna. Austria.Google Scholar