Not 0K, but pretty cool.

[Scripter]

Well, the update claims to have fixed this, but I am still unable to get this one to pop.

Cooling is not an issue. I have a loop to keep super coolant at a nice warm 3K - 5K range consistently.

So I am curious: What counts as a "building"?
And when is the actual calculation made? (mine seems to be stuck at 13.1 kelvin. )
And is the calculation a peak (or valley) at any time or an average over time or...?

EDIT: fixed some typos

[Bokonon]

I haven't done it but I'm pretty sure you can get this by pumping some really cold super coolant. The pump will cool to the necessary temp and is considered a building.

[Scripter]

On a quick investigation it would seem that the temperature measurement is only taken upon loading a game. (Got so close... 6.5K)

[Scripter]

For now I would confirm that the calculation is done ONLY on fresh start load. (Loading from within a game does not seem to work. )

Got 4.1 Kelvin. And it would seem that an ambient temperature sensor will be enough. (the thermo sensor you find in the automation buildings)
(the afore mentioned pump was at 5.8 Kelvin)

So for someone still struggling with this:
This is A way:
(note: drains an absolute crap ton of power)

Build a 2 block high and 3 block wide insulated reservoir to which you can dump super coolant. Within the reservoir put:
- a large pump
- thermo sensor. (at the bottom row)
- A liquid vent. (at the top row)
- (optional) diamond temp shift plates on the background. mainly affects temperature exchange speed to both directions.
Connect the thermo sensor directly to the pump.
Pull the pipes through the walls to pour directly on the thermo sensor (not that there'd be any room elsewhere)

The pump will push the supercoolant straight out of the reservoir.
Use the best insulated piping you can easily afford. The best is not necessary.

Outside the reservoir:
This is the challenging part:
Route the supercoolant by temperature to loop through aquatuners until it is at 16 Kelvin.
As the aquatuners only cool by 14 Kelvin per unit, anything cooler needs to be warmed back up, and anything warmer needs to be first cooled down and then warmed up to meet said 16 Kelvin.

And as the liquid is at 16 Kelvin, Route it through one last aquatuner which dumps it directly to the reservoir.

The thermo sensor within the reservoir can be set to around above 8 Kelvin so it shuts down the heat producing pump as the temperature is getting close to the spot.

When the temperature of either the pump, or thermo sensor drops below 6 Kelvin, Save, exit the game, restart the game and load the save.

Hopefully this helps someone else.