The ECMWF data centre in Bologna sits inside the Manifattura Tabacchi, a former tobacco factory protected as industrial heritage. Its arches and historic envelope could not be structurally altered, so the data centre was built as a self-contained unit within the existing building: a high-performance facility inside a 19th-century shell.
Cooling is delivered by air cooling units that draw warm air from the data hall, pass it through water-cooled coils and push chilled air into an underfloor plenum, from which it rises through floor grilles to the server racks. The project followed a design-build approach and was pursuing LEED certification, which called for simulation showing that the HVAC system could keep safe operating conditions across the data hall, in normal operation and in failure scenarios.
We built a CFD model of the data hall and ran four scenarios: two in normal operation and two with half of the cooling units offline. Failure scenarios show what nominal operation can hide, such as specific rack positions left unprotected the moment a unit goes down. The results led to changes made during design, before construction: floor grilles repositioned for better air distribution, and cabinet doors adjusted for more efficient airflow through the racks.
Outside, the roof-mounted chillers shared space with the diesel generator exhausts, and at certain wind angles exhaust gases reached the chiller intakes. We modelled this interaction and verified a fence enclosure that blocks the exhaust without restricting the chillers' own air intake.
