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The sunlight exposure represents one of key parameters of indoor climate comfort. The evaluation of sunlight access into buildings is based on a methodology of European standard EN 17037. The methodology is focused on specification of an insolation time which would comply with requirements for the sunlight expo sure of permanently occupied spaces like houses and residential buildings as well as schools or hospitals. The sunlight exposure evaluation is recommended to be between 1st February and 21st March. The specific date from the interval can be selected for individual evaluations. This is a relatively long period of days in which the insolation could vary meaningfully. The aim of this study is to evaluate how the sunlight exposure might be changed in the recommended standard period in dependence on the geographic locality and climatic conditions in the Central Europe region. It depends on the sunlight time and specific design situations as well as shading obstructions. The review of the sunlight exposure is determined. The review results can perform information about design possibilities for the sunlight exposure in real buildings in the given climatic locality. [ABSTRACT FROM AUTHOR]

A comprehensive study of straight light pipe efficiency and illuminance distribution below ceiling level is performed using HOLIGILM tool. The recommendations for light guide systems can be made for different latitudes and sky luminance patterns using the data computed here. The computational results show that the light pipe transmittance is a monotonic function of solar altitude, except for low-sun angles. Redistribution of photons at the light pipe base can be characterized by a scalar value called “asymmetry parameter”, g . A use of g is an efficient attempt to the classification of a large number of luminous intensity distributions. The minimum value of g is at low solar elevations (between 10° and 30°) because of balanced contribution of diffuse light of a sky and the direct sunbeams. The low values of g indicate the redistribution of light is more uniform. Luminous intensity solid determined by means of HOLIGILM tool is used to compute illuminance distribution at a working plane. The peak intensity and intensity gradient of a bright ring projected onto a working plane can be used to characterize the optical properties of different light pipes in different climatic zones. [ABSTRACT FROM AUTHOR]