Modelling of Daylight Sources in the Artificial Sky

Abstract:

Daylight in nature is characterized by daily permanent changes of sunlight and skylight. Real measurements of daylight availability are showing that different daylight exterior illuminance for building interiors can be expected each minute. This brings some complications in the window design and the choice of criteria for daylight evaluations. There are several ways how to find basic conditions and typical relations combining sunlight beam with diffuse skylight from the whole sky vault. The older assumption considered that interiors have to be sufficiently illuminated under the worst overcast conditions. The newer approach is based on the utilization of daylight in specific localities and the determination of changes in sunlight and skylight occurrence probability. Therefore, both daylight sources are researched in detail specifying sky luminance distributions and sun influences to find conditions for their simulation in laboratory facilities. The most sophisticated equipment to study daylighting in exterior and interior architectural spaces are artificial skies with the artificial sun. These have to be precisely calibrated with a verified zenith luminance and horizontal illuminance levels by theoretical calculations and checked by experimental measurements. Reference daylight conditions defined in the ISO/CIE 15469:2004 standard have to be respected with trials to determine natural sun and sky as sources of daylight in the real environment and modelling these in the artificial sky in a certain intensity scale. This paper presents the method and results of modelling daylight applying electrical light sources in artificial sky which is installed in the Institute of Construction and Architecture, Slovak Academy of Sciences (ICA SAS) and discusses possibilities of their simulation in laboratory conditions.

• Periodical: Applied Mechanics and Materials (Volume 861)
• Pages: 469-476
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.861.469
• Online since: December 2016
• Authors: Stanislav Darula*, Richard Kittler, Marta Malikova
• Keywords: Artificial Sky, Calibration of Artificial Sky, CIE General Standard Sky, Daylight Sources, Daylighting, Sun

References

[1] STN 73 0580-1: 1987. Denné osvetlenie budov. Časť 1: Základné požiadavky. (Daylighting in buildings. Part 1: Basic requirements). ÚNM, Praha.

[2] ČSN 73 0580 – 1: 2007. Denní osvětlení budov. Část 1: Základní požadavky. (Daylighting in buildings - Part 1: Basic Requirements). ČNI, Praha.

[3] DIN 5034-1: 2011. Tageslicht in Innenräumen - Teil 1: Allgemeine Anforderungen (Daylighting in indoors – Part 1 – General requirements).

[4] BS8206-2: 2008. Lighting for Buildings - Part 2: Code of practice for daylighting.

[5] Information on http: /idmp. entpe. fr.

[6] D. Dumortier, M. Fontoynont and P. Avouac-Bastie, Daylight availability in Lyon. Proc. of the European Conf. on Energy Performance and Indoor Climate in Buildings, Lyon, 1994, pp.1315-1320.

[7] H.D. Kambezidis, Th. Oikonomou and D. Zevgolis, Daylight climatology in the Athens urban environment: guidance for building designers, Lighting Res. Technol. 34 4 (2002) 297.

DOI: 10.1191/1365782802li037oa

[8] A. Bartzokas, S. Darula, H. Kambezidis and R. Kittler, Sky luminance distribution in Central Europe and the Mediterranean during winter period, J. of Atmospheric and Solar-Terrestrial Physics. 65 1 (2003) 113-119.

DOI: 10.1016/s1364-6826(02)00283-3

[9] S. Darula, R. Kittler, Occurrence of standard skies during typical half-days, Renew Energy. 33 (2008) 491-500.

DOI: 10.1016/j.renene.2007.03.029

[10] P. Tregenza, Standard skies for maritime climates, Lighting Res. Technol. 31 3 (1999) 97-106.

DOI: 10.1177/096032719903100304

[11] D.H.W. Li, C.C.S. Lau and J.C. Lam, Standard skies classification using common climatic parameters, J. of Solar Energy Eng. Trans. of the ASME. 126 3 (2004) 957-964.

DOI: 10.1115/1.1740776

[12] M.B. Kobav, G. Bizjak, Development of a substitutive light source for indoor daylight calculations, Build Environ. 40 12 (2005) 1611-1618.

DOI: 10.1016/j.buildenv.2004.12.013

[13] R. Kittler, R. Perez and S. Darula, Sky classification respecting energy - efficient lighting, glare and control needs. Proc. IESNA Annual Conf. Cleveland. IESNA, New York, 1996, pp.71-84.

DOI: 10.1080/00994480.1997.10748167

[14] M. Perradeau, Climat lumineux à Nantes. Analyse des mesures effectuées en 1991-1994. EN-ECL 94-14L Report. Nantes: CSTB, Décembre, (1994).

[15] N. Igawa, H. Nakamura and Y. Koga, Classification method of measured sky luminance distribution data. Proc 23 Session CIE, 1995, pp.230-231.

[16] ISO 15469: 2004(E)/CIE S 011/E: 2003. Spatial Distribution of Daylight - CIE Standard General Sky. ISO, Geneva, CIE, Vienna, (2004).

DOI: 10.25039/ds011.2003

[17] R. Kittler, S. Darula and R. Perez, A set of standard skies, Polygrafia Publ., Bratislava, (1998).

[18] S. K. Wittkopf, A method to construct Virtual Sky Domes for the use in standard CAD-based light simulation software, Architectural Science Review 47 (2004) pp.275-286.

DOI: 10.1080/00038628.2000.9697533

[19] J. Mardaljevic, Simulation of annual daylight profiles for internal illuminance, Lighting Res. Technol. 32 (2000) pp.111-118.

DOI: 10.1177/096032710003200302

[20] D. Croghan, Transilluminated domical artificial sky, Light and Lighting 57 (1964) pp.290-293.

[21] C. Aghemo, A. Pellegrinoand and V.R. M, LoVerso, The approach to daylighting by scale models and sun and sky simulators: A case study for different shading systems, Build. Environ. 43 (2008) p.917–927.

DOI: 10.1016/j.buildenv.2007.01.020

[22] M. Navaab, Scale model photometry techniques under simulated sky conditions, J. of the IES Summer (1996) p.160-(1972).

[23] L. Michel, C. Roecker and JL. Scartezzini, Performance of a new scanning sky simulator, Lighting Res. Technol. 27 (1995) pp.194-207.

DOI: 10.1177/14771535950270040401

[24] Information on http: /sites. cardiff. ac. uk/architecture/about-us/facilities/environmental-lab/sky-dome.

[25] Bartenbach. Artificial sky. Künstlicher Himmel, Bartenbach, Innsbruck, (2015).

[26] Information on http: /www. donau-uni. ac. at/en/department/bauenumwelt/lichtlabor/13096/ index. php.

[27] M. Bodart, A. Deneyer and V. Gilbert, Validation of the Belgian single-patch sky and sun simulator. Build. Environ. 43 (2008) p.1892–(1901).

DOI: 10.1016/j.buildenv.2007.11.005

[28] R. Kittler, New artificial overcast and clear sky with artificial sun for daylight research, Lighting Res. Technol. 4 (1974) pp.227-229.

DOI: 10.1177/096032717400600407

[29] CIE 22: 1973. Standardisation of luminance distribution on clear skies. Technical Report, CIE Central Bureau, Paris, (1973).

DOI: 10.25039/tr.022.1973

[30] Information on http: /www. lumidisp. eu.

[31] DALI USB Bridge. IlumTech, Dojc, (2016).

[32] ASC V2. 1. Artificial Sky Calibration program. (L. Komar, Calibration of the artificial sky using images. Proc Conf. Lumen V4, 2016, in print).

DOI: 10.1109/lumenv.2016.7745554