Does anyone have any experience with solar control window film use/installation? As far as I know it's a film applied to the inside of a window to reduce heat/glare. Basically our bedroom has 2 impractically large windows: one is 3.5 x 1.5m and east facing. The result is that the room gets incredibly hot and uncomfortable to sleep in, in warm weather. My queries are: does it significantly reduce heat, can it be applied to double glazing, is it very obvious externally and is it a permanent fixture once applied to the window? Thanks