Technology Transfer Department

Application sectors

Problem to solve

The technology of high-reflectance cement-based materials aims to address two main problems—high energy consumption for summer cooling and the urban heat island effect—while also meeting a growing need for urban and energy sustainability, as outlined below: - Create more resilient, sustainable, and livable cities, particularly in the face of climate change. - Reduce the environmental impact of the building sector, one of the main sources of energy consumption. - Improve urban quality of life through smart materials that interact with the environment (e.g., by reflecting heat, draining water, and adapting to climate conditions). - Support ecological transition and decarbonization policies, including through incentives and minimum environmental criteria (CAM).

Description

In areas with high levels of solar radiation, reducing the amount of solar energy absorbed by the building envelope is helpful in lowering the need for air conditioning and mitigating the “urban heat island” effect. Most high-reflectance products, however, suffer from poor durability. According to several studies, overheating—both at the urban and building scale—is strongly influenced by construction materials, which can reach temperatures up to 40?°C higher than the surrounding air, resulting in significant heat flows both into and out of buildings. To counter this phenomenon, known as the “urban heat island effect,” and the resulting increase in electricity consumption in buildings—particularly during the summer—we tested the use of materials with high solar reflectance (SR), the so-called Cool Materials (CM), for the “passive cooling” of buildings. These materials can reduce the surface temperature of structures exposed to solar radiation and limit the heat flow entering the building. The analyses conducted led to interesting conclusions regarding the effectiveness of high-reflectance materials, especially when combined with other mitigation actions—for example, the simultaneous application of CM on building façades and road pavements, and the presence of vegetation elements on buildings (e.g., green roofs) and in urban areas (e.g., gardens or tree-lined streets). The study, carried out through dynamic simulations, highlighted promising perspectives in terms of response to direct solar radiation: the energy savings achievable during the summer season show significant potential in most of the tested climate zones. On an annual energy balance, the benefits are notable in regions with hotter summers, while they are modest in colder or temperate climates.

Research group involved