Nano-tech based cool materials for building energy efficiency

Cool materials represent an interesting and acknowledged solution able to produce a threefold benefit: the reduction of cooling energy needs in buildings, the mitigation of the urban heat island phenomenon, the counterbalance of global warming trend at larger scale. In fact, they are environmentally friendly and relatively cost-effective materials characterized by high solar reflectance and infrared thermal emittance properties. Therefore, they are helpful to mitigate the urban microclimate by decreasing air and surface temperature when applied over building envelopes, i.e., roofs and walls, and urban paving surfaces. This chapter will discuss about the key research contributions to the development and testing of such cool materials’ effectiveness with a specific focus on the material engineering and characterization. More in details, the recent nanoscale developments will be addressed and the main applications of cool materials will be discussed in order to provide quantitative and quantitative assessment of the effectiveness of such technology for building energy efficiency.