Fall is a nice time to get some RV camping in but we have experienced a lot of heat loss from the two large side windows on our BT5210 particularly through the night being they are not thermo pane.
Decided to insulated them with Reflectix foil insulation with favorable results, thus keeping the cabin much warmer.
I removed the 10 inside vertical frame screws and replaced with threaded snap receptors...per window
Cut the insulation and added the mating snap buttons to the foil.
Quick and easy to install each foil panel with minimal heat loss!
To store the two panels We just roll up and store in the closet adjacent to the rear door.
Foil sheet on roll :Amazon
Snap button kit: Amazon
Hole puncher for foil snap buttons :Amazon or Harbor Freight
Couple this mod with a heavy weight sliding curtain isolating the front cab and high 30's outside is do able for over nighters without furnace constantly running.
Yes I had to purchase a 120 piece set as it was the smallest qty. Use the short screw receptor in the frame
As an assembly aid I made a template from a narrow piece (2" wide) of 1/4" plywood for the snap spacing. I made the hole locations wide enough to fit a Sharpie tip so can easily located the locations to use the hole punch.
No need to put snaps on the top and bottom. Just make the foil panel longer there to extend beyond the window by 2".
You will need to grab the foil snap firmly to lift it off the mating window snap receptor upon panel removal.