Experimental Investigation of the Impact of Improved Ducting and Chassis Re-Design of a Hybrid-Cooled Server

In recent years, there has been a significant increase in cloud computing, networking, virtualization, and storage applications, leading to an increase in demand for high-performance servers. The increase in performance demands is currently being met by increasing CPU and GPU power densities that require more efficient cooling technologies as compared to air traditional cooling methods. Cold plate-based liquid cooling in air-cooled servers enables efficient thermal management with minimal changes to existing air-cooling infrastructure. In a hybrid cooled server, the demand for air cooling is reduced as the primary heat-generating components are indirectly cooled by cold plates. In this study, experiments are performed with optimized chassis of a hybrid cooled Cisco C220 server. The chassis design is optimized to improve the airflow by providing additional vents on the chassis to allow more low-temperature airflow rather than the heated airflow approaching from the drive bay. Also, the design of the heat sink baffle is improved which allows a more streamlined flow to approach the heat sinks. This is done by designing and manufacturing a new 3-D printed baffle. This optimized baffle design helps in reducing the pressure drop across the system hence helping in the reduction of fan speeds and reducing the fan power consumption. Results are generated by iterating the fan speed and inlet temperature of air and comparing them with the baseline design of the server. Conclusions are made on the reduction in fan power due to the improved chassis design and any reduction in temperatures of air-cooled components.