The effects of cool materials, façade orientation, and morphological parameters on energy consumption at the residential neighborhood scale

Building surface cool materials are novel materials that can reduce urban heat island intensity and decrease building energy consumption. This study investigated the impact of radiative properties of materials, façade orientation, and morphological parameters on energy consumption in six typical residential neighborhoods in Nanjing, China. The neighborhood energy consumption of 16 application schemes considering the façade orientation factor is compared to determine the best energy-saving scheme. Seasonal and annual energy-saving rates, savings in electricity costs, and the price ceiling for materials per unit area are analyzed. The results show that for low-rise buildings, using cool materials only on the roof can reduce the annual energy consumption by 1%. When cool or super cool materials are also used on the building façade, the annual energy saving rate can be up to 3.4% and 4.3%, respectively. Using cool materials on the south façade of buildings is not recommended due to significant heat loss in winter. Considering savings in electricity costs and the price ceiling for materials per unit area, the price of cool and super cool materials should be less than 3.0 and 3.7 RMB/m², respectively, assuming a lifespan of eight years in Nanjing.