Intelligent Data Centres Issue 28 | Page 22

INDUSTRY INTELLIGENCE POWERED BY THE DCA
Providers of cooling equipment for data centres highlight their control systems as one of their most important and unique selling points . Digital control of the cooling systems has grown to become elaborate but can be seen as the differentiator when acquiring a supplier .
H2020 funded project called BodenType DC ( project 768875 ), a direct fresh air data centre was constructed in Boden , Sweden and operated for one and a half years where cooling control strategies could be developed and tested together with the collection of operation telemetry .
Two partners , RISE AB and EcoCooling Ltd , respectively an expert in server operations based in Sweden and a direct fresh air cooler manufacturer based in the UK , managed to create a holistic data hall were operated with a targeted CPU temperature and the same 120- hour server digital workload profile was operated first with native server fan control and then with the targeted CPU temperature of 70 ° C .
The servers reported all fan speeds to a Modbus server along with individual power consumption of each server that was constantly read by the EcoCooling direct fresh air-cooling control system , which in turn tuned the supply and extract fans to match the accumulated air consumption of the 480 servers .
Taking over the control of the fans in servers is perhaps not regarded as mainstream , but modern servers do offer some degree of control over their fans at the BIOS level .
However , the holistic cooling control strategy , even without the overridden server fan control , does produce a more responsive cooling system as has been
Dr Jon Summers , DCA Advisory Board and Scientific Lead in Data Centres at Research Institutes of Sweden
cooling control strategy simply by taking control of the cooler supply and extract fans synchronously with control of all the server fans .
The holistic cooling control strategy makes use of the affinity laws of fans , half the speed of rotation of the fan uses only one-eighth of the fan power – the socalled cube law . Slowing down the server fans was achieved at the server level using a small PLC that interrupted the fan signal communication with the server and imposed a slower speed to target an imposed constant CPU temperature . All 480 servers in the BodenType DC
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