Temp-Shift plates do not work in vacuum

Heat transfer is

Cell-Cell - e.g. granite tile next to oxygen ( vacuum = 0)

Cell-building - e.g. pipe and oxygen around it OR tempshift plate(counted as building) and oxygen around it ( vacuum = 0)

• Note there's no direct heat transfer between pipe and tempshift plate, even if they occupy the same square

Cell-entity - debris/dupes + oxygen (vacuum => transfer with bottom cell with coefficient 1/4)

Building-content - e.g. pipe + water inside

So in case of vacuum, you're in bad luck! Only debris transfer heat, and they do it with 1/4 the speed of normal cell-entity transfer.

Another case where transfer happens is sweeper-content(even if sweeper is in vacuum).

So .. sorry to say, but I think that's intended behavior. There was a thread about cooling stuff near space recently, so you can read that too

 

Edited August 6, 2018 by martosss

Actually, this whole thing looks like something different now. It was not vacuum, as piping in 500g of Hydrogen did change nothing. It seems to me now that the Neutronium base of the steam vent caused this. After 200 cycles the crass differences have gotten far less, but the plates next to the Neutronium are kept at an almost constant temperature. 

Edited August 7, 2018 by Gurgel
typo