Since the minimum requirements for thermal insulation of glazing units are increasing as a result of necessary energy saving measures in the building sector and conventional types of glazing have reached their limit, the interest in new and energy-saving types of glazing is growing. A VIG-Hybrid is such a new highly insulating glazing unit that can achieve U-values of 0.3 W/m-2K-1. It is a combination of two existing glazing types: a standard Insulating Glass Unit (IGU) and a VIG. In such a unit, the advantages of both insulating structures are combined: The slenderness of the VIG with simultaneous high insulation and the flexibility of an additional situationally adaptable outer glass layer with a gas-filled intermediate gap.
Since it is a structure with regions of non-uniform temperature distribution in-plane and across the thickness due to varying ambient temperatures and solar radiation, the energy (heat) paths must be well understood to efficiently design such a VIG hybrid and to evaluate the resulting stress in the glass. It is known, in the triple pane IGU, that the in-plane temperature difference due to solar radiation between the cold edge shaded by spacers and frame, and radiation-exposed parts of the glass surface, can lead to thermal breakage of this pane. Therefore, the resulting stresses for the VIG-Hybrid are investigated and, in particular, the center pane of the VIG hybrid. In this work, experimental and numerical results for thermal induced stresses in VIG-Hybrids are presented.
