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Talks and Poster Presentations (with Proceedings-Entry):

S. Dervishi, A. Mahdavi:
"Comparison of Models for the Derivation of diffuse Fraction of Gloabl Irradiance Data for Vienna, Austria";
Talk: Building Simulation 2011 - IBPSA 2011, Sydney, Australien; 2011-11-14 - 2011-11-16; in: "driving better design through simulation - Proceedings of the 12th Conference of The International Building Performance Simulation Association", V. Soebarto, H. Bennetts, P. Bannister, P.C. Thomas, D. Leach (ed.); Konferenzpublikation mit wissenschaftlichem Lektorat, (2011), ISBN: 978-0-646-56510-1; 765 - 771.



English abstract:
To compute the irradiance intensity on building
surfaces, information on both direct and diffuse
component of solar radiation necessary. Available
measured data are, however, typically restricted to
global horizontal irradiance. There have been thus
many efforts in the past to develop algorithms for the
derivation of the diffuse fraction of solar irradiance.
In this context, the present paper compares eight
different models for estimating diffuse fraction of
irradiance based on a database of measured
irradiance data from Vienna, Austria. These models
generally involve mathematical formulations with
multiple coefficients whose values are typically valid
for a specific location. Subsequent to a first
comparison of these eight models, three better
performing models were selected for a more detailed
analysis. Thereby, the coefficients of the models
were modified to account for Vienna data. The
results suggest that some models can provide
relatively reliable estimations of the diffuse fractions
of the global irradiance. The calibration procedure
could only slightly improve the modelsī
performance.

German abstract:
see english version

Keywords:
irradiance, diffuse irradiance, models, simulation, measurement