Microchannel Cooling

Microchannel cooling is an extension of direct-to-chip cooling that involves the addition of cold plates that directly target CPUs, GPUs, and memory modules. Sealed metal plates spread the heat generated in a device into small internal fluid channels that enable the cooling of a larger surface area. It is commonly achieved with the aid of a heatsink with a high conductivity substrate that contains many parallel, small diameter channels.

These channels may be skived or pin fin channels in nature. Most microchannel solutions require a thermal interface material (TIM2) to be applied when connecting to a heat-generating component. The enhanced surface area and fluid contact with the cold plate allows for a high level of heat removal. However, sometimes the thermal interface material can be a limiting thermal resistance layer as thermal design power (TDP) reaches peak performance levels.

A microchannel heat exchanger is the core of the microchannel liquid cooling process. It consists of two headers (the inlet and outlet headers), flat microchannel multiport tubes, and fins that are brazed together with non-corrosive fluxes. These elements are comprised of aluminum alloys and can differ in numbers and sizes depending on the required performance and application.

Key Benefits of Microchannel Cooling

Although a relatively new innovation for data center cooling, microchannel liquid cooling has significant benefits for data centers as it allows for improved performance and increased energy efficiency. This is because it increases heat transfer between the fins in the heat exchanger and the ambient air. Overall, it is reported to provide 20% to 40% greater overall heat transfer performance than other methods. Additionally, microchannel cooling allows for the maximization of space capacity utilization as the heat exchangers are 10% to 30% smaller in size and up to 60% lighter in weight than other heat exchangers.

Other benefits of microchannel liquid cooling include

• High heat transfer coefficients. A heat transfer ratio refers to the amount of heat transferred per unit area per kelvin, and the higher the coefficient, the more efficient the equipment. One reason for a higher coefficient is the brazed assembly method used to manufacture the heat exchangers. Brazing allows for a metallurgical bond between tubes and fins, eliminates contact resistance, and therefore ensures greater heat transfer.
• Low refrigerant charge. Compared to a traditional finned tube heat exchanger, a microchannel heat exchanger has a significantly lower internal volume. This is because microchannel heat exchangers use tubes less than 1mm in diameter. This reduction in volume improves the ecological safety of the equipment and reduces end costs by limiting the use of harmful refrigerants.
• High corrosion resistance. Microchannel heat exchangers are protected by e-coating, which is a process that uses an electrical current to deposit an organic coating from a paint bath onto a heat exchanger. This coating can penetrate recesses and reach geometrically complex parts, providing protection against corrosion for all of the equipment’s components. These heat exchangers are also relatively easy to clean due to their low thickness that does not require any disassembly, protecting the exchanger from corrosion caused by contamination.
• Lower equipment cost. The above-mentioned advantages allow for the overall reduction of equipment costs due to smaller heat exchanger sizes, reduced refrigerant charges, the use of smaller fans, and a reduction in the number of parts needed to run the equipment. Also, microchannel liquid cooling allows for the direct expansion systems to operate without a refrigerant distributor, a component that is both fragile and expensive. Overall, research indicates that microchannel heat exchangers allow for a 10% reduction in costs in comparison to traditional heat exchangers.

Cool Your Data Center Efficiently with DCIM Software

Data Center Infrastructure Management (DCIM) software collects, reports, and alerts on data from power and environmental sensors to ensure that the data center is being cooled efficiently.

Key aspects of DCIM software that contribute to a more efficient cooling system include:

• Measuring and monitoring data center energy consumption for more intelligent management decisions for the facility
• Environment monitoring to better understand the current conditions and determine what areas need improvement
• Tracking power, environment, energy, and cost data in real-time to monitor the impact of data center energy efficiency initiatives on KPIs
• Data center automation capabilities, zero-configuration charts and reports, and visual analytics that aid in reducing energy consumption

Want to see how Sunbird’s world-leading DCIM solution can help you efficiently cool your data center? Get your free test drive now!