Field test of cooling systems in two air-cooled data centers: Various regions, air distributions and evaporative cooling technologies

Global data center electricity consumption constitutes 0.9–1.3 % of total demand, contributing to the importance of energy saving and waste heat recovery. A field test was conducted on two air-cooled data centers to assess their energy consumption and cooling system performance, providing valuable support for optimization. Power usage effectiveness (PUE) collected during peak summer conditions of conventional data center 1 varied from 1.274 to 1.291, with an extrapolated annual average of 1.2118. Analysis of energy consumption distribution indicated that information technology (IT) servers accounted for 78 % of the usage, followed by the cooling system at 13.9 %, the electrical system at 3.6 %, and auxiliary systems at 4.5 %. In contrast, data center 2, which relies on a year-round free cooling approach using indirect evaporative chillers, achieved an average PUE of 1.26 and allocated 13.8 % of its energy consumption to cooling. Notwithstanding, the efficiency of its cooling system is notably compromised by inadequate cold aisle containment and the scaling in the cooling water system. Post-optimization improvements are projected to reduce data center 2′s PUE to 1.155. Both data centers suffer from prevalent issues such as suboptimal IT load rates, improper segregation of hot and cold airflows within server rooms, and compromised cooling water quality.