Radiance of the circumsolar and background parts of skydome for buildings under random obstructions

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

2 Scopus Citations
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Author(s)

  • Isaac Y.F. Lun
  • Yu Huang
  • Dawei Xia
  • Yanping Yang

Detail(s)

Original languageEnglish
Article number110796
Journal / PublicationEnergy and Buildings
Volume236
Online published1 Feb 2021
Publication statusPublished - 1 Apr 2021

Abstract

The diffuse radiation on building envelopes can be essential to the thermal environment and the energy study of buildings. Because a part of the skydome can be obstructed irregularly in city environments, the diffuse radiance distribution over the skydome should be determined to evaluate the radiation accurately. In this study, this distribution is described by several representative sky directions to specifying the radiance variation features over the skydome, especially the attenuation around the sun. The irradiance of each sky element (normalized by the horizontal diffuse) is correlated to the routine global radiation and the solar altitude as an all-sky model for simple engineering uses. According to two sets of one-month field measurements (in different sites) of the vertical irradiance under irregular obstructions in the hot and humid Hong Kong, the coefficient of determination (R2) is 0.041 and 0.142 higher than the classical single-direction anisotropic diffuse model that is adopted by many simulation tools, and the R2 difference can be up to 0.38 for partly cloudy days. When compared to the distribution models, the R2 outperformance of the proposed model can still be 0.057. The proposed approach is thus effective to the solar radiation studies in the city environments.

Research Area(s)

  • Diffuse radiation, Irregular obstructions, Radiance distribution, Urban environment