I love the 3 ways for the propane option when boondocking. 40 should be good. A fridge is a fridge not a freezer.
Also, if you start with cold food in there and keep it relatively full with food and drinks, it will probably get colder.
Also, if its REALLY hot out, I've frozen water in half gallon juice jugs(perhaps smaller water bottles in your case) and then put them in the fridge.
I freeze one in the gas freezer and then rotate it with another in the fridge after it thaws.
This keeps temps down even on the hottest days(basically you're just giving it an ice box boost.)
But both fridges and freezers tend to work better with quite a bit of stuff in them and smaller ones work best when the stuff added is already cold as their recovery is very slow due to the small size of their mechanicals.
|