Long-term hygrothermal monitoring of glass fiber Vacuum Insulation Panels for roof application

In this study, the first outcomes of a research activity aimed at the experimental evaluation of the long-term thermal behavior of VIP applied in a roof test room TRIS (Testing Roofing Innovative Systems) are presented. The working conditions (temperature and relative humidity) over the VIP, which are the main drivers of the gas and water vapour diffusion in the evacuated core, were continuously monitored, while the thermal conductivity is measured before and after one-year operation. Moreover, a comparative analysis, for the winter season, with a roof element with traditional polystyrene insulation of the same thickness was carried out. The measured data can be used, on the one hand, for the robust validation of newly developed service-life prediction models for glass fibers VIPs and, on the other hand, to evaluate if the performance decay over time, might jeopardize the fulfillment of the minimum insulation requirements enforced by technical standard or laws. The final goal is to verify if the glass fibers VIP-containing getters can be a practical, reliable, and durable solution for the building envelope insulation.