Dual impacts of solar-reflective façades in high-density urban areas on building energy use and outdoor thermal environments

Chenshun Chen, Julian Wang, Huijin Zhang, Xinyue Xu, Laura Elizabeth Hinkle, Xiao Chao, Qian Shi

Research output: Contribution to journalArticlepeer-review

Abstract

In the context of rising urban temperatures, this investigation delves into the impacts of solar reflectance on glazed facades, shedding light on urban microclimates and the resulting thermal experiences. Recent retrofit strategies have employed low emissivity and high solar reflective materials to enhance energy efficiency and indoor comfort against climbing outdoor temperatures. Despite these advances, adverse effects on outdoor heat conditions are often reported due to the intrinsic relationships among the glazed facades’ optical and thermal properties, highlighting a gap in thorough, quantitative assessments in this domain. Accordingly, this study aims to bridge this gap, examining the comprehensive effects of glazed facades’ solar reflectance on building energy performance and the Universal Thermal Climate Index (UTCI) in densely populated urban settings. Utilizing computational simulations and empirical analysis, we scrutinized changes in outdoor solar radiation, ground temperature, UTCI, and building-specific energy demands, including heating, cooling, and lighting energy use, correlating these with varying façade's solar reflectance levels during peak summer periods. Results affirm the potential of highly solar reflective facades to substantially cut cooling energy needs by mitigating solar heat gain and thermal conductance. However, a notable byproduct is the upsurge in UTCI, signaling increased heat stress risk within urban canyons. Our comprehensive, multi-objective optimization approach seeks to harmonize the solar reflectance of facades, aiming to reconcile energy conservation with the imperative of maintaining urban thermal comfort. This research contributes significantly to urban retrofit strategies and also guides the potential sustainable urban and landscape design that harmonizes urban energy savings with the mitigation of urban heat implications.

Original languageEnglish (US)
Article number114926
JournalEnergy and Buildings
Volume324
DOIs
StatePublished - Dec 1 2024

All Science Journal Classification (ASJC) codes

  • Civil and Structural Engineering
  • Building and Construction
  • Mechanical Engineering
  • Electrical and Electronic Engineering

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