Understanding the performance metrics for advanced cooling methodologies

Many novel thermal management technologies have been developed to ameliorate the losses from modern electronics. As these techniques are developed, designers endeavor to compare each method with existing concepts. However, many of these comparative metrics can be system-dependent, leading to inconclusive results. One of the most common metrics, the thermal resistance, is a simple relationship between the total heat transfer from a device and its temperature rise above a reference condition. However, the thermal resistance metric has several issues that can limit its utility in comparing systems, particularly due to its dimensional nature and consequent dependence on system size. In addition, this metric does not include any information about the amount of power required for cooling a system. To improve comparisons, a non-dimensional volumetric coefficient of performance is proposed, accounting for issues such as thermal performance, system extent, and input power requirement. This new parameter is compared with other common metrics in the examination of two promising contemporary cooling solutions: synthetic jet air cooling and micro-channel liquid cooling.