Optimization of top-floor rooms coupling cool roofs, natural ventilation and solar shading for residential buildings in hot-summer and warm-winter zones

Abstract

The high building energy-saving potential of integrated passive technologies has drawn significant public attention. This paper combined field measurements and multi-objective optimization to reduce lighting and air conditioning (AC) energy by coupling cool roofs, natural ventilation (NV), and solar shading. Experimental measurements verified the cooling effects of cool roofs and NV based on thermal performance. The influences of cool roofs on heating and cooling energy were obtained. A building simulation model was validated by measurement data of thermal performance and AC energy use collected from a Guangzhou residential building. Energy-saving potentials under NV and daylight implemented strategies were then quantified. Compared to the black room without energy-saving strategies, daylight could reduce lighting energy by 3.3 kW h/(m2·yr), and AC energy use could be reduced by 4.7, 22.7 and 26.9 kW h/(m2·yr) in the black, blue and white rooms adopting NV, respectively. The roof albedo, roof insulation thickness and window-to-wall ratio notably impacted AC and lighting energy based on global sensitivity analysis. Optimal design schemes based on multi-objective optimization could reduce the top-floor room energy consumption by up to 52.3 kW h/(m2·yr).