Those who have those - what temperature delta have you achieved ?
And what kind of divider do you have ?
I'm using ISO foam 1 3/8" (for now) and can get 15 deg.
I was expecting to double the foam to 2 3/4" to have get to a 30 deg delta.
I'm still ferm chamberless. But I think your assumption is about right, assuming you have really good insulation to the outside temp. Also any air leaks will really change things.
making (C6H10O5)n- into C12H22O11 and then into C2H5OH, and then getting drunk
Box (outside) insulation is 2.75" of ISO too. That should be like a R16-18.
Of course, the fridge is only about an inch.