Power consumption minimization in hybrid cooled server by fan reduction

The energy consumption in a typical data center is rising day by day to meet the increasing demand of high compute servers resulting in high energy costs. In typical data centers, almost half of the IT energy is dedicated to cooling of the IT server racks. Hybrid cooling technology as an approach to minimize the power consumption uses of water or water based fluid to cool a high heat generating component whereas the rest of the components is cooled by air using internal fans. In this paper, our objective is to optimize the flow rate of air cooling loop of such hybrid cooled server to make data center cooling more cost effective and energy efficient. The volume of air supplied is controlled by varying the air flow rate through the internal fans. Also, the number of fans is reduced from five to three to minimize the power consumption. This finding helped us realize the 40% decrease in Fan power for each server. The pressure difference between the cold and hot aisle is created to avoid the backflow of cold air. Parameters like CPU and memory utilization were varied and temperature of different components such as processors, Dual-In-Line-Memory Module (DIMMs) & Platform Controller Hub (PCH) was monitored. When the server is running with 3 fans (approx. 10 CFM) maximum temperatures are found below the critical temperature. Further studies are also carried out through CFD analysis to observe changes in a model in 6SigmaET to increase the cooling efficiency. The study gives an idea of power savings by fan consolidation for energy efficient hybrid servers.