A regular exchange of air is necessary to maintain work safety in the chemical laboratories. The air has to be completely replaced eight times an hour using a ventilation system, which also leads to heat losses.

At the German Climate Computing Center, climate researchers calculate their complex climate simulations on the high-performance computer Mistral, which produces a waste heat during its operation. Since November 2019, the colling water of the supercomputer has been transferring the produced thermal energy to the ventilation system of the neighboring chemistry laboratories using heat exchangers. The water is fed through a pipe system into the Bundesstrasse 45. The heat is transferred from the water to the supply air via so-called heat exchangers. This air is afterwards fed to the laboratories and heats the room air.

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Left: View of the heat exchangers in the intake tower for drafts, with which the waste heat from the DKRZ supercomputer Mistral is transferred to the chemistry laboratories (photo O. Cantürk). Right: A second transmission point is on the roof of Bundesstrasse 45 and supplies the pharmacy laboratories (Photo: DKRZ).

In the first year since it started operation, a total of 3,500 megawatt hours of thermal energy were saved. In comparison: a single-family house consumes an average of 25 megawatt hours of thermal energy per year. This corresponds to savings of around 1,000 tons of CO2 per year. This value is comparable to the CO2 emissions of 62 households in one year if two people live in the apartments.

For the second year of operation in 2021, some optimizations are planned for the heat exchange, so that even around 4,000 megawatt hours of thermal energy might be saved.