Reducing CO2 emissions by improving HVAC system efficiency of data centers through nanofluids: a case study

• Data center energy consumption accounts for a significant portion of global energy consumption. • A major problem for data centers is the dissipation of heat generated by computers. • An extended experimental campaign has been carried out on a real data center. • We demonstrated the increase in HVAC system efficiency of a data center through the use of a nanofluid. Nowadays, energy conservation is a crucial issue because of its many benefits, such as reducing greenhouse gas emissions, decreasing dependence on energy imports, and reducing costs for households and businesses. Data center energy consumption accounts for a significant portion of global energy consumption and may increase dramatically in the next years with the growing popularity of compute-intensive applications such as A.I., video-on-demand services, autonomous vehicles and advanced 5G technology. A major problem for data centers is the dissipation of heat generated by computers, for which various cooling systems are used. The objective of this work is to demonstrate the increase in cooling system efficiency directly attributable to the use of an aluminum oxide-based heat-transfer nanofluid, resulting in cost and energy savings and therefore in greenhouse gas emission reduction. In this investigation, through an extended experimental campaign, the comparison in terms of COP between a baseline period (before installation of the heat transfer nanofluid) and a reporting period (after installation), maintaining the same heat load, was shown. Measurements demonstrated an average COP improvement of 9.1 %, confirming the effectiveness of nanofluid in improving chiller efficiency. This result demonstrates that the use of nanofluids in HVAC systems serving data centers can help significantly reduce CO 2 emissions while containing energy costs. In order to strengthen the conclusions of the present study, through an LCA analysis, greenhouse gas emissions related to the aluminum oxide nanofluid filled into the plant were calculated, finding 14.3 tons of CO 2 , compared with an annual CO 2 emission reduction of 50.9 tons/y. Finally, considering the expected electrical output of data centers in the next years, the global average CO 2 emission factor, and the increase in chiller performance related to the use of nanofluids, the maximum achievable result in terms of global GHG emission reduction was calculated, yielding 16.5 Mt CO 2 .