Comparative Study on Simulation of Daylighting Under CIE Standard Skies for Different Seasons
- 141 Downloads
This paper deals with the comparative study on daylight availability on horizontal working plane of a simulated room under identified CIE (International Commission on Illumination) Standard skies prevailing in Roorkee, India for the three seasonal conditions, viz. equinox, summer, and winter solstices. Daylight coefficient method (DC) and finite element method (FEM) have been applied to develop computer programs in MATLAB environment for this simulation. Here daylight availability is predicted for a room with single-sided window of opening areas 20% of floor area and sill height 1 m from floor with eight cardinal window orientations. Analysis revealed that during summer the amount of daylight availability is maximum as the sun shines directly on the Northern Hemisphere during summer. Polar axis of earth is tilted 23.5° to the orbital plane. Differential and changing illumination pattern on earth for different seasons is due to combinations of rotation, revolution, and tilt of polar axis.
KeywordsCIE standard skies Sky component computation Daylight coefficient method Finite element method Rotation and revolution of earth
The author wishes to acknowledge the support received from Dr. R. Kittler and Dr. Danny H. W. Li since they sent their publications which helped to complete this research. She also likes to thank Indian Society of Lighting Engineers [ISLE] and Mr. P. K. Bandyopadhyay, past President, ISLE for providing a copy of the report  published by Central Building Research Institute [CBRI] containing Indian Measured Daylight Database.
- 2.Li DHW, Lau CCS, Lam JC (2011) A simplified procedure using daylight coefficient method for sky component prediction. Arch Sci Rev 14(3):287–294Google Scholar
- 3.Investigations on evaluation of daylight and solar irradiance parameters for improved daylighting of buildings and energy conservation in different climates. Central Building Research Institute [CBRI] (2001)Google Scholar
- 7.Darula S, Kittler R, CIE general sky standard defining luminance distributions. Institute of Construction and Architecture, Slovak Academy of Sciences 9, Dubravska Road, SK—842 20 Bratislava, SlovakiaGoogle Scholar
- 11.CIE—Commission Internationale de l′Éclairage (2003) Spatial distribution of daylight-CIE Standard General Sky. CIE Standard S 011/E. CIE Central Bureau, ViennaGoogle Scholar
- 13.Debashis Raul, Sujoy Pal, Biswanath Roy (2015) Application of Perez daylight efficacy model for Kolkata. J Inst Eng India Ser B 96(4):339–348Google Scholar
- 14.Littlefair PJ (1992) Daylight coefficients for practical computation of internal illuminances. Light Res Technol 24(3):261–266Google Scholar