Keystone Montana factory tour.
They use Reflectex (silver coated bubble wrap) for insulation. I think it has an R factor of 3?
The Coroplast also provides some protection.
Tanks at 3:55 and 9 minutes
Bottom insulation 7:20 and 8:35 and 12:38 minutes.
Water line routing/insulation 12:38 minutes.
Racetrack AC ducts 32:42min.
https://youtu.be/cV0OZv0bCgc
Home with the Hoppers factory tour
https://youtu.be/o0W2PeLlUBY