There is always a problem in the winter in an older attic apartment, which is that the skylight sweats a lot overnight. In the morning, the windshield and its frame are very wet.
The indoor temperature is about 18 degrees Celsium. The skylight is closed from the inside of the room with a tight blind. There is about 25 cm of "space" between the blinds and the glass. The room itself is small, about 6m2.
Does the window sweat so much overnight because the blinds separate the skylight from the air in the room?
It would not work without the blackout as it would be too bright (street lighting).
This was also the case in the previous house. The skylight was wet or frozen around the edge in the winter when it was very cold, the glass was only double-glazed. But in our case, it was only a heated pantry of about 6 square feet. My solution was a simple mini fan (no heater!) that kept blowing into the window . That helped.
Ventilation is the easiest. Just enough to let the air in the room move around so the moisture can escape.
6 m2 of space and the air that you breathe is too little, you can leave the door open, or leave the heating on, or leave the window ajar for ventilation.
The window is just too poorly insulated and therefore too cold inside. Either get a new window or towel it off in the morning.
Need more heat. And ventilate what you can.
Use heating tape to gently heat the glass from the inside around the edge of the glass overnight.
Attach the heating tape to the styrofoam plate around the perimeter and across the inside and then clamp it to the glass (between the frame). This means that the window should warm up a bit and can no longer freeze from the inside.
Looks like winter in a mobile home (panel van). The windshield behind the louvers is full of condensation in the morning. Wipe it off and well – you can do it in the house. When the window is through – replace it with a more insulated one – as long as the dew point is not below the dew point on one of the walls.