A case study of the effect of building surface cool and super cool materials on residential neighbourhood energy consumption in Nanjing

Abstract

Cool materials for building surfaces have been invented to reduce building energy consumption. This study aimed to investigate the impact of cool and super cool materials on the energy consumption of residential neighbourhoods in Nanjing. First, the impact of microclimate on building energy consumption simulation is investigated. An energy correction model is obtained to consider the impact of microclimate factors when energy consumption is calculated using meteorological data. Compared to meteorological data, the wind speed in the microclimate data for the urban centre is significantly lower, and the temperature is significantly higher. In addition, the seasonal and annual energy saving rates of cool and super cool materials in six typical residential neighbourhoods are analyzed. The results show that cool and super cool materials are very effective for reducing building energy consumption in summer, with energy saving rates of up to 13.85 % for cool materials and 17.74 % for super cool materials. However, building energy consumption increases in winter when using cool and super materials, so it is necessary to evaluate the energy saving effect of cool materials based on annual energy consumption. Overall, for residential neighbourhoods in Nanjing with a sky view factor less than 0.45, the annual energy saving rate is 1.95 % for cool materials and 2.35 % for super cool materials. The conclusions of this study can provide a guide for energy conservation policy in residential neighbourhoods in Nanjing.