Hi just found this after googlng double glazed windows steamed up. Our upstairs windows are just awful at the moment. They steam up so much in the evening when we goto bed and in the morning I have to wipe them all over. We are now getting damp patches in the corner of our bedrooms. I was told to leave a window slightly open but when its -4 and we have a baby that isn't the greatest of ideas. I always leave them wide open when we get up to clear them but this is getting me down now as theres little wet patches on the window sill. Please help!