It has to do with the arrangement of the compressor. The compressor generates a lot of heat, and is located at the bottom of the appliance. With a bottom freezer, that means the compressor is much closer to the freezer and it's much harder to keep that heat out of the freezer.
Maybe one day we’ll have a refrigerant network in a home that refrigeration could tap into, but the cost of specialization will probably exceed the savings :(
Or maybe run a municipal water loop into the fridge? Many are almost there when they have an ice machine (which is also horrible for efficiency).
Or in a cold one - it strikes me as some variation of insane that I have a box in my house that heats the room by trying to freeze the contents when it is -30º outside.
You fundamentally misunderstand your matryoshka doll of insulated boxes!
In winter, you don’t want to bring in very cold stuff from outside the big box into a smaller box inside the big box: the net effect is you’re making the overall big box colder.
Heat pumps are very efficient!
Though your argument holds up if electricity is expensive and heat is cheap (e.g. off grid with woodstove heat)
If anything, you want to bring stuff from outside the big box, put it in the little box to chill further (dumping the heat inside your big box), and then toss out the super chilled stuff from the little box out of the big box.
What I want to do is put the little box outside the big box in winter, though I suspect all the "waste heat" the freezer/fridge "burns up" offsets the gas used to heat the house somewhat.
All in all it's too complicated to work out, but I will admit to leaving frozen goods in the trunk in the winter because of laziness.
Becomes a problem when everything freezes in the warmer littler box inside the little box.
But nooooooooooooo, bring the warmish frozen stuff into the little box inside the big box in winter ASAP. (Unless, like I said, you're offgrid with unlimited trees)
