An aircraft window mounting assembly having a pressure pane in abutting contact with an inner surface of an exterior pressure pane frame. A bezel is proximate a periphery of the pressure pane and defines an inner opening. The bezel includes an inner wall, an outer wall, an exterior wall, and an interior wall. A dust cover is proximate the interior wall of the foam bezel. An electro-optic element is disposed in the opening and is configured for reception by the inner wall. The pressure pane, the foam bezel, and the electro-optic element define an exterior cavity. The bezel, the electro-optic element, and the dust cover define an interior cavity. A first relief passage is in fluid communication with the exterior cavity and the interior cavity. A second relief passage is in fluid communication with the interior cavity and one of an aircraft interior cabin and an aircraft wall.