Evaluation of 5 years' performance of VIPs in a retrofitted building façade

The challenges to retrofit buildings urges for technologies and novel building materials to be developed. In many cases the space for additional insulation in the building envelope is limited. Vacuum insulation panels (VIPs) have a significantly lower thermal conductivity than conventional insulation materials which means less thickness is required to achieve the targeted thermal transmittance. VIPs have been used in buildings since the late 1990s and there exists experience from using them in numerous applications. Besides the higher initial cost for using VIPs in buildings there is still hesitation among architects and engineers whether this component will withstand long-term use in buildings. Therefore further investigations are needed to evaluate its long-term performance. This paper presents experiences from a case study of a previously non-insulated wall insulated with VIPs. Measurements of the temperature and relative humidity in the wall during 5 years show no sign of deterioration of the VIPs and there is a low risk for condensation in the construction. The measurements are continuous with the aim to determine the long-term performance of VIPs in building applications.