Impact of Improved Ducting and Chassis Re-design for Air-Cooled Servers in a Data Center

In recent years, there has been a phenomenal increase in cloud computing, networking, virtualization, and storage, leading to the rise in demand for data centers. There is a need for the latest computing nodes to meet this demand, which causes an increase in power consumption. The cooling system occupies almost 30%-40% portion of the total energy consumption. Per ASHRAE TC 9.9, IT equipment needs to operate within recommended and allowable temperatures (18-27°C) and humidity zone based on the cooling classes (A1-A4). As the inlet air temperature increases, fan power consumption increases. The Central Processing Units (CPUs) and high heat-generating components inside each server must operate at their respective reliable operating temperatures. In most cases, air cooling is used in a data center, and it becomes difficult to maintain lower component temperatures at lower airflow rates with increase in Thermal Design Power (TDP). A chassis design optimization is performed over the chassis structure of the air-cooled server to provide better airflow for the cooling of the main components. Vent openings are provided on the sides of the server to bypass the front placed hard drives and provide additional airflow paths. Parametrization was performed for the hole diameters, area of perforation, and operating speed for fans while considering Electromagnetic Interference (EMI) best practices and following guidelines to avoid stress concentration on mounting rail and chassis situated in a rack. An improved duct is proposed and implemented inside a 1U server (Cisco C220 M3) to find a sweet spot between the trade-off of an increase in pressure drop across the server and junction temperature of components. Overall, the study evaluates the new duct and the redesigned chassis with side vents by showcasing the simulated results showing the reduction in the fan speeds by 38% and thus increasing the savings of fan power consumption by 72%, achieving a maximum of 16% drop in component temperatures.