How long do you run your genny to keep freezer frozen?

The Dometic F540 was an excellent 1.5 CF freezer. Kept food consistently -5F at 100F ambient temps. They cost $500 back in the late eighties.

Insulation is the key for a freezer. Think of it this way - a freezer is nothing more than a refrigerator with an insulation attitude.

Cruising sailboats sometimes utilize expensive glass panel vacuum insulation. A quarter inch thick vacuum panel = 12" of closed cell foam.