Influence of internal pressure equalization on static quantities in climatically loaded insulating glass units

Insulating glass units (IGUs) are a specific building element. The inability to equalize the pressure of gas cavities with atmospheric air generates loads, related to changes in weather conditions during the operation of the IGUs. The associated loads may pose a problem in the context of using multi-glazed IGUs. The use of devices that equalize the pressure with the environment has limited effectiveness, due to the possibility of deterioration of the IGUs’ thermal performance. The article examines an intermediate solution involving internal pressure equalization between the cavities. The aim of this study is to analyze how this solution affects the static values in the component panes. Selected configurations of the IGU structure and loading were investigated. The vertical and horizontal location of the IGUs were considered, taking into account the possibility of a radiative temperature drop on the external surface of the glazing. It was found that internal unsealing of the cavities is beneficial in the case of equal thicknesses of the outer panes. In the analyzed cases, the calculated extreme deflection and stress dropped even above 20%. IGUs with one of the outer panes thickened behave differently. In this case, the appropriateness of using internal unsealing depends on which pane has been thickened. In the most unfavorable configuration, internal unsealing of IGUs can lead to an increase in static quantities by more than 45%. It was also found that the factors intensifying the effects of climatic loads are: horizontal location of the IGUs and different thicknesses of the outer component panes.