We often camp in pretty cold conditions – subfreezing but not sub-zero. On a recent winter trip, we realized that the frosted window inset into the trailer door was losing a lot of heat. So when I got home, I rigged up a way to hold a foam insulating pad on the inside of that window. I think that other folks who camp in cold weather might find this useful.
As I do on our other windows, I used foam flooring material (from Costco), which comes in interlocking panels (about 2 feet square), cut down to fit the window opening. The foam is about a half inch thick and is fairly stiff. The window in our trailer's door was about 21 inches by 15 inches. (Actually, I measured it in millimeters to give myself the illusion of precision.) I cut the pad to size with a box cutter:
The next issue is how to hold the pad in place? I thought about Velcro or magnets (my best friends) but decided to string four strands of monofilament fishing line (10 lb. test, I think) across the window to contain the pad. Here is a shot of the pad on the door:
And this is a close-up of one of the monofilament cross-strings:
In order to create the cross-strings, I first took out a screw (one at a time!) and stuck one end of the string into the hole:
(By the way, please excuse the greasy fingers -- that's what my hands look like on a "garage day.")
I then screwed the screw back into the hole, trapping the end of the monofilament:
In order to install the insulating pad, just slip one end under the lowest string and slide it up into place. Remove it by sliding it down. We store it under one of the dinette cushions -- a little extra padding never hurt anything.