Vacuum insulation panels (VIP) is a high performance thermal insulation material solution with thermal conductivity values reaching as low as 4.0 mW/(mK). With time the thermal performance of the VIPs will degrade as moisture and gas permeate through the barrier envelope of the panels. To better evaluate these ageing effects, accelerated ageing experiments are needed. VIPs consist of a porous core of pyrogenic silica (SiO2) and a gas and vapour tight envelope. The external factors that are found to contribute most to ageing of VIPs are temperature, moisture and pressure. Several experiments have been initiated to evaluate the acceleration effects by the application of severe temperature, moisture and pressure conditions, including: 1. Thermal ageing at 80°C for 180 days according to CUAP 12.01/30 2. Exposure to cyclic climate in a vertical climate simulator according to NT Build 495. One VIP sample is fully exposed in the simulator and one is placed in a wooden frame structure. 3. Exposure to high vapour pressure by storage at 70°C and 90-100 % RH for 90 days. The increases in thermal conductivity during ageing were relatively small compared to the initial thermal conductivity of the VIPs, which is in agreement with the theoretical predictions. The temperature and moisture experiment seemed to achieve a rather large acceleration effect. In addition, the thermally aged VIP and the exposed VIP in the climate simulator show physical alterations. E.g. swelling, curving and delamination of the outer fire protection layer are observed.
Nanotechnology and possibilities for the thermal building insulation materials of tomorrow are explored within this work. That is, we are looking beyond both the traditional and the state-of-the-art thermal building insulation materials and solutions, e.g. beyond vacuum insulation panels (VIP). Thus advanced insulation material (AIM) concepts like vacuum insulation materials (VIM), gas insulation materials (GIM), nano insulation materials (NIM) and dynamic insulation materials (DIM) are introduced and defined. The VIMs and GIMs have closed pore structures, whereas the NIMs may have either open or closed pore structures. The objective of the DIMs are to dynamically control the thermal insulation material properties, e.g. solid state core conductivity, emissivity and pore gas content. In addition, fundamental theoretical studies aimed at developing an understanding of the basics of thermal conductance in solid state matter at an elementary and atomic level will also be carried out. The ultimate goal of these studies will be to develop tailor-make novel high performance thermal insulating materials and dynamic insulating materials, the latter one making it possible to control and regulate the thermal conductivity in the materials themselves, i.e. from highly insulating to highly conducting.