I've had plexi glass hung over top of windows, but they were on the outside of the glass, bolted to the window frame, to prevent large waves from breaking or punching your windows out. They offer little help on the inside.
Insulation is the answer as the heat loss through the windows is substantial. It also reduces condensation if a desiccant of some kind is placed between the windows.
Insulation is the answer as the heat loss through the windows is substantial. It also reduces condensation if a desiccant of some kind is placed between the windows.
I put them up before I crossed the Atlantic (1/2" Lexan on the outside) with the intent to take them off upon arrival.
Four years later, they are still on, though I have resealed them a couple of times.
I discovered that being in cool climes like Northern Europe, they totally cut out any condensation.