Nanotech based vacuum insulation panels for building applications

Abstract

Vacuum insulation panels (VIP) represent a state-of-the-art high-performance thermal insulation solution. The pristine non-aged centre-of-panel thermal conductivity value for a VIP can be as low as 0.002-0.004W/(mK) depending on the core material. Normally, declared average values accounting for thermal bridge effects and ageing during e.g. 25years are to be given, typical an effective thermal conductivity value between 0.007 and 0.008W/(mK) for VIPs with fumed silica cores. VIPs enable highly insulated solutions for building applications, both for the construction of new buildings and for the renovation of existing buildings, and may hence be a measure to reduce the energy usage in buildings without having to employ very thick building envelopes. This study gives a state-of-the-art review of VIP products found available on the market today and explores some of the future research possibilities for these products. The application of nanotechnology is regarded as a promising pathway for achieving and improving both vacuum and non-vacuum based high-performance thermal insulation materials. During the last years, VIPs have been utilized with success for building applications in increasing numbers, where one of the main driving forces is the increased focus on e.g. passive houses, zero energy buildings and zero emission buildings. Thus, VIPs are now in the early market stages as a building product. The implementation of VIPs in various building constructions has lead to an increased interest in the utilization of this product, both in new and refurbished constructions. Even though there is not enough data to conclude the effect over a lifetime of a building yet, the immediate result in decreased energy usage can be seen. However, the challenges of guaranteeing a set of lifetime expectancy, along with high costs, are some of the major reasons why VIPs are met with a certain scepticism in the building industry. Aiming to give better quality assurance for the users, make further advances in VIP envelope technologies and the development of VIP core materials, along with a further cost reduction, represent crucial aspects for VIPs to become a competing thermal insulation solution for buildings.