Simple method for determining daylight illuminance in a heavily obstructed environment

A review of daylight illuminance determinations and energy implications

“…Tregenza also proposed simple calculation procedures for determining the daylight illuminance in rooms facing sunlit streets [129]. Calculation models of vertical daylight illuminance in a heavily obstructed environment under overcast and non-overcast skies were formed [130,131]. The sunlight reflected by vertical facades and ground can represent an important source in the illumination of buildings.…”

Artificial illumination during daytime in residential buildings: Factors, energy implications and future predictions

“…External light reflected from nearby buildings and sunlit streets were further modeled to estimate mean daylight illuminance in rooms facing sunlit streets [27]. Further research was carried out to model indoor illumination under high density urban residential buildings where windows face varied obstructions [28,29]. Perez et al [30] developed an 'All-Weather' model for Berkeley with five variable coefficients depending upon sky clearance, sky brightness and solar altitude based upon the original model by Perez [31].…”

Illuminance Level in the Urban Fabric and in the Room

“…The method used in this paper is based on the VDF method developed by Li et al [6,7] to determine the illuminance on a vertical fac¸ade.…”

“…The fac¸ade reflectance was simulated as an average value, averaging the reflectance of the windows, walls, framing, etc. A fixed ground reflectance of 0.2 was found to be a reasonable assumption for dense urban areas [6], so the ground reflectance was set to 0.2.…”