This is what i plan to do:
Add as much external insulation as will fit between the outside side walls and top of the fridge and the cabinet it’s mounted in. My fridge has at least an inch to an inch and a half that is uninsulated all around it. If need be I’d pull out the fridge, put maximum insulation in the cabinet, and slide the fridge back in to make it easier. Use the foil faced rigid stuff if possible.
I’d stay away from adding insulation in the interior. It’s not sanitary or necessary.
Add a very quiet 12 volt
computer fan or two (or three for that matter) plus a thermal switch and a manual cutoff switch to push more air out of the upper fridge side vent door (or up the roof vent if you have one) to reduce the excess heat buildup in the upper back of the fridge compartment. The cooler the absorption system on the back of the fridge is, the better it works.
If you have an awning that shades the fridge side of the Airstream, deploy it whenever possible and safe to do so. Shade makes a big difference. (Our fridge is under our curbside awning. I also try to park that side to the east to minimize heat gain in the afternoon)
Rich, KE4GNK/AE, Overkill Engineering Dept.
'The Silver HamShack' ('07 International 22FB CCD 75th Anniversary)
Multiple Yaesu Ham Radios inside and many antennae sprouting from roof, ProPride hitch, Prodigy P2 controller.
2012 shortbed CrewMax 4x4 Toyota Tacoma TV with more antennae on it.