Just above the metal tiles there are two mechanized airlocks, then a whole square bounded by manual airlocks, all from gold amalgum. That square is infinistore for bring from a cool salt slush geyser, at temperature -10c.
The thermo sensor in the little hole in the metal tiles? It opens those two mechanized airlocks when it's cold enough -- 23c -- and closes them again when it needs more cooling.
It's what we call a "heat injector", tho in this case it's injecting cold.