Refrigerator improvements

[HappyNomads]

Have any of us figured out how to squeeze longer RV refrigeration times out of a single tank of propane? Or boost its performance in a hot climate?

I tried an experiment with a standard AC house freezer --- and lowered the temp from a "standard" 5-10 degrees down to -11 to -2 degrees, while cutting total power consumption in half. That freezer can now withstand several days without power and keeps the food frozen.

I added 2" foil-backed insulation (foil on both sides. Polyiso in this case.) selectively to the INSIDE side walls. This cuts into the remaining space bigtime. But it was worth it. Obviously stay well away from any area or sensors that need ventilation to distribute the cold.

In this home freezer I also insulated the outside of the rear (no built-in coils, just foam core), and the outside of the front door (also no coils) but had to avoid the outside walls and top, which contain coils that radiate the heat out. On these side walls I added interior insulation to further distance those heat radiating coils from the frozen food inside, as I mentioned above.

This worked so well I did a similar thing to the Igloo cooler we carry in the TV. It now sits on a 2" foil-backed sheet, has another sheet between the cooler and the inside wall of the vehicle and a third sheet covering the top of the cooler.

The result: a bag of ice now lasts three days instead of one.

What might I safely do to a 7 cu foot Dometic unit with a separate freezer and a refrigerator compartment. Put the insulation on the left and right walls of both, staying well away from the fins and the thermistor?

[rmkrum]

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)