Experimental and Numerical Investigation on Thermal Performance of Data Center via Fan-wall Free Cooling Technology

With the rapid increase in the scale of data center (DC) construction, DC air conditioning energy consumption has attracted wide attention over the past years. As the DCs are located in the mild climate regions, the air-side free cooling technology that combined with the fan wall air supply demonstrates excellent energy-saving potential. However, there are quite few reports on the environmental thermal response of air conditioning in fan-wall DCs. In this article, the effect of both supply air volume (SAV) and supply air temperature (SAT) on the temperature control performance of the DC are tested through a newly built small fan-wall DC facility. The effect of supply air parameters and the DC’s total power (DCTP) are further investigated through numerical simulation. The results show that the server inlet air temperature increases linearly with the SAT and the DCTP, whereas decreases logarithmically with the SAV. The optimal SAV is 0.5 m3/s for a single rack with 2.5 kW when the SAT is 27 °C. Based on the Rack Cooling Index (RCI) evaluation method, an empirical SAV correlation is established and verified against other numerical cases for fan-wall DCs when taking the SAV, the SAT, and the DCTP into account. In the current study, according to the developed model, approximately 34% energy consumption of fans could be saved for fan-wall DCs.