Logan Shaw said:
What about making the butter compartment sort of an airlock between the fridge
and the outside?
You dont really need an airlock. My 1950s fridge already
has a butter compartment, but it doesnt work very well,
basically because they attempt to do the temp in there
using a relatively primitive approach of a plastic door on it.
It wouldnt be hard to replace that with something decently
insulating with polystyrene foam instead, and a small heater.
Then have motorized shutters that open on either side (the fridge side or the
outside) if the butter compartment gets either too cold (open shutter to
outside) or too hot (open shutter to fridge)?
I'd rather a decent modern thermostat control on the heater.
Completely trivial to do with the onewire thermostat ic.
It seems better than running a heater when relatively warm air from the
outside is available for free most of the time.
True, but its easier to do with a simple heater than mechanically
modify the fridge when its just got one door to the outside.
Probably best to keep it outside the fridge in winter,
and only inside the fridge in summer when the butter
ends up at too high a temp outside on the benchtop.
And I agree with the other comment someone else made about
butter getting rancid too quickly in summer out of the fridge. Specially
with the relatively low rate at which the butter is consumed here.