Your Data Center is Under Water and Hotter than Ever

Anyone who’s jumped in a cold pool on a hot day understands the effectiveness of liquid cooling. This is certainly not a new concept.  Automobile radiators, one of the first examples of liquid cooling in industry, have existed for nearly 125 years.  Using liquid cooling – among other temperature-reduction methods – is not a novel idea for the data center either, where uncontrolled heat from servers, high-powered processors and a myriad of electronics gear could cause serious issues.  While data center liquid cooling applications have been relatively limited to specific high-heat systems, compute-intensive and data-intensive workloads of new server configurations continue to drive temperatures higher, placing more interest on more broadly-applied liquid thermal management approaches. 

The physical design of the data center prioritizes heat reduction because, when it comes to electronic systems, high temperature is a performance-killer and a potential system-destroyer, too.  While the absolute environmental temperature limit of the data center is 82° F, according to some industry recommendations, the ideal temperature range should fall somewhere between 73° - 75° F. [1]   As you can imagine, that makes for a big air conditioning bill, not to mention a significant drain on the power grid.  Ensuring server systems (and other electronics) are controlled as much as possible for temperature is, therefore, critical not only for the uninterrupted storage and processing of data, but for more energy-efficient, lower-cost operations as well. 

In addition to active air cooling (air conditioning, fans, etc.) and optimized structure designs such as raised floors that help maximize air flow opportunities, cooling electronic systems – particularly in server racks – from the inside out is equally vital.  The use of thermal interface materials (TIMs), heat sinks and liquid cooling systems within high-density server electronics are the primary methods for achieving in-application temperature reduction.  For all of these approaches, massive innovation is underway as data volumes and speeds driven by AI, data mining, and analytics are only getting more intense – and hotter.

Data center operators are driven not only to manage performance optimization through heat reduction, but also to ensure more sustainable, energy-efficient data factories. There is just so much air cooling can achieve when power densities are high.  Liquid cooling amplifies the temperature reduction equation and is doing so with recirculated (i.e. waste-reducing) water or coolants that are highly effective.  This lowers the drain on power significantly. The question is:  Can the positive effects of liquid cooling be made even more substantial? 

In the past, attempts have been made to further improve the heat dissipation of liquid cooling systems by using TIMs between the component and the metal liquid cooling pipes/plates/chassis.  This accelerates heat dissipation between what would otherwise be metal-to-metal contacts.  This idea has merit.  Unfortunately, the thermal interface materials available – in the form of pads, adhesives, gels and liquids – are either not suitable (gels and liquids) for the application or cannot withstand the friction (pads and adhesives) often induced by pluggable components into the housing and/or the PCB being inserted into partitioned, liquid-cooled plate structures. The materials are pushed or scraped off and essentially become ineffective.