Optimization of coupled building roof solar reflectance and thermal insulation level for annual energy saving under different climate zones

Abstract

The aim of this work is to assess building energy performance optimization potential of cool roof solutions in different climate conditions worldwide through dynamic thermal-energy simulation and optimization analysis. Moreover, given the dependence of roof performance on insulation level, the influence of roof insulation variation on optimum roof solar reflectance is evaluated. Therefore, the multi-dimensional optimization of combined building roof solar reflectance capability and thermal insulation level is carried out to minimize annual energy consumption for air-conditioning of standard ASHRAE building model for small offices, in each considered climate zone. Findings of this research highlight how the classic approach of super-insulated buildings for energy saving needs to be reframed for the office case, by integrating other passive solutions for truly environmentally friendly and comfortable buildings.

The research leading to these results has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement N°657466 (INPATH-TES). The work is partially funded by the Spanish government (ENE2015-64117-C5-1-R (MINECO/FEDER) and ENE2015-64117-C5-3-R (MINECO/FEDER)). The authors from the University of Lleida would like to thank the Catalan Government for the quality accreditation given to their research group (2014 SGR 123). Anna Laura Pisello’s acknowledgments are due to the UNESCO Chair “Water Resources Management and Culture”, for supporting her research. Alvaro de Gracia would like to thank Ministerio de Economia y Competitividad de España for Grant Juan de la Cierva, FJCI-2014-19940.