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The dynamic nature of today’s data centers requires active monitoring and holistic management of all aspects of the facility, from the applications to the air conditioning. The most significant aspect of implementing a dynamic data center is the requirement to actively monitor and manage the infrastructure assets. It is vital to ensure information technology (IT) equipment has access to sufficient air (provisioned) at a proper temperature to assure their optimal and continues operation. Hot air recirculation, elevated fan speed, and hot spots are known consequences of an under-provisioned cold aisle. On the other hand, over-provisioning a cold aisle can lead to a significant loss in energy due to bypass of cooling air and leakages. Besides, the number of active servers in an aisle may be varied by load balancers due to short or long-term IT load changes. This demonstrates the need for an active airflow management scheme that is able to respond to airflow demand in different aisles of a data center. In this study, remotely controllable air dampers are implemented to regulate airflow delivery to a cold aisle containment (CAC) during workload changes in a data center. The energy saving opportunities are investigated and practical considerations are discussed. 

Miniaturization of microelectronic components comes at a price of high heat flux density. By adopting liquid cooling, the rising demand of high heat flux devices can be met while the reliability of the microelectronic devices can also be improved to a greater extent. Liquid cooled cold plates are largely replacing air based heat sinks for electronics in data center applications, thanks to its large heat carrying capacity. A bench level study was carried out to characterize the thermohydraulic performance of two microchannel cold plates which uses warm DI water for cooling Multi Chip Server Modules (MCM). A laboratory built mock package housing mock dies and a heat spreader was employed while assessing the thermal performance of two different cold plate designs at varying coolant flow rate and temperature. The case temperature measured at the heat spreader for varying flow rates and input power were essential in identifying the convective resistance. The flow performance was evaluated by measuring the pressure drop across cold plate module at varying flow rates. Cold plate with the enhanced microchannel design yielded better results compared to a traditional parallel microchannel design. The study conducted at higher coolant temperatures yielded lower pressure drop values with no apparent change in the thermal behavior using different cold plates. The tests conducted after reversing the flow direction in microchannels provide an insight at the effect of neighboring dies on each other and reveal the importance of package specific cold plate designs for top performance. The experimental results were validated using a numerical model which are further optimized for improved geometric designs.