Abstract: A window structure includes a pair of panes of glass maintained in spaced apart relationship by a separating unit to define an interior chamber between the panes substantially impervious to the ambient atmosphere. The separating unit includes a pressure equalization device for controlling the volume of the chamber to maintain the interior chamber pressure substantially equal to the ambient atmospheric pressure. The separating unit can also include a desiccant-filled container in fluid communication with the chamber for dehydrating air within the chamber.

Abstract: An appliance comprising a unitary, atmospheric pressure, equilization chamber and drying chamber in the form of a sealed, flexible walled container with open cell elastomeric material providing communication between the interior of the chamber and the zone between facing surfaces of adjacent panes of glass.

Abstract: An appliance comprising a unitary, atmospheric pressure, equalization chamber and drying chamber in the form of a sealed, flexible walled container is provided with means communicating from its interior to the space between a double glazed window. A separable coupling between the container and the space permits replacement of the appliance when its drying capability is exhausted. Window frame contructions unobtrusively incorporate the appliance in a cavity which has a removable cover. Variations in atmospheric pressure are balanced within the space between the window lights by changes in the atmospheric pressure on the flexible walled container while such changes transfer gas between the space and the container to expose it to the desiccant. One separable coupling passing the gas is a hollow needle inserted through a resilient, self-sealing, passage which can be integral with a seal gasket between the lights.

Abstract: A window construction containing two or more panes of glass with an enclosed air space therebetween and means for mounting the panes to effect a seal therebetween despite differential expansion or contraction due to temperature and barometric pressure changes. Gas directing means are provided for effecting an efficient flushing of the enclosed space between the panes of glass. Pressure equalizing means are provided for equalizing the internal gas pressure within the enclosed space with the atmosphere.