Glass is an indispensable building material because of the special properties. Glass has a low heat resistance and therefore it is a thermal leakage in the outer wall. Insulated double glass reduces the heat transfer tremendously. The closed air in the hermetically closed cavity is a good insulator. The magnitude of the pressure in a hermetically closed cavity is an unknown parameter. What is the cavity pressure if the temperature changed, ambient pressure changed, under a uniformly distributed load, under a concentrated load and the like? These influences were investigated by an analytical model and were verified by experimental research
