Integrated thermal-energy analysis of innovative translucent white marble for building envelope application

Marble is a natural and precious material, which has been used in construction field since ancient times. It has always been used as massive construction element, and its peculiar aspect gave the idea of monumentality and solidity. Nowadays new technologies permits to the marble to express new languages: in particular, translucent marble technology overturns the concept of solidity. To achieve the translucent effect, marble is cut into thin layers and let the light pass throughout its surface, thanks to its natural crystalline structure. The main problematic limiting the diffusion of this application is the lack of thermal energy efficiency of the stone element as the only façade component, due to its reduced thickness. On the other hand, this element could bring advantages to the energy performance of the building, if carefully applied. In fact, “”Bianco Carrara” and “Statuario” marble for instance are permeable to light and they could be considered as naturally cool material for their intrinsic light color and high thermal emissivity. In this perspective, this paper analyzes the combined energy aspects of thin marble as external envelope skin for a new designed building for arts activities located in New York City. An integrated analysis of the energy performance of the marble skin is performed by mean of a preliminary experimental characterization of solar transmittance, absorbance, reflectance and thermal emissivity. These measurements are taken for two different types of white marble, in order to achieve a comparison between the two. The influence of the polluted environment on the marble envelope is also taken into account: a comparison of the performance before and after marble degradation due to acid aggressive environment, typical of acid rains of a big city, is assessed. Therefore, the thermal-energy assessment of the building is carried out in a dynamic simulation environment, in order to evaluate the year-round benefits and penalties of translucent marble envelope for lighting and air-conditioning.