Abstract: The insulated window construction is characterized in having a substantially uniform heat transition coefficient. The uniformity of the heat transition coefficient is obtained by increasing the distance between the window panes and the heat resistance in the edge region of the window is matched to that in the region of the window area which is undisturbed by the edge. The edge region is formed by a frame which has a pair of separate metallic frame members which are joined together and spaced apart by non-metallic webs so as to define an insulation path of at least 0.8 times the clearance between the panes.

Abstract: The double pane window is provided with a drying chamber which is filled with desiccant and an antechamber which extends from the drying chamber to communicate with the surrounding environment at the opposite end. The antechamber prevents a direct exit of dry air from the enclosed space between the window panes into the surrounding atmosphere during "breathing" of the window as well as drawing in of moist ambient air into the drying chamber. The antechamber also brings about a considerable increase in the diffusion resistance for the water vapor diffusion into the desiccant or the space between the window panes.

Abstract: A single foil is biaxially stretched on a frame for movement relative thereto by being secured intermittently to a single rubbing strip over a guide ledge. The rubbing strip is stretchable and movable lengthwise of the associated frame side. Torsional forces arising because of the one-sided loading of the frame by the stretched foil are taken up by the frame which is made with a torsionally rigid cross-section.The single foil can be clamped without creasing and in a manner which ensures freedom from creasing notwithstanding differences in the heat expansion of the foil and frame.