Energy-efficient data center solutions with liquid-cooled servers

With the growth of the digital economy, data is becoming the new oil. The evolving landscape has resulted in the proliferation of data centers, an imperative from the business continuity planning standpoint, coupled with the evolution of innovative cooling technologies, a sine qua non for the uninterrupted functioning of data infrastructures.
liquid-cooled serversDemanding workloads, space constraints, a widening demand-supply gap, increased power consumption, high storage density, harsh IT environments, and layout design challenges are forcing data centers to seek efficient sustainable alternative solutions to the presently dominant air-cooled servers. This holds especially true in the case of high-density racks that require considerable high-power GPUs and CPUs, making air-cooling, a less viable option, on grounds of both applicability and cost.

Consequently, liquid-cooled servers are gaining popularity due to their distinct advantages over the conventional air-based cooling systems. A study indicates that the global data center liquid cooling market is estimated to grow from $1.2 billion in 2019 to $3.2 billion in 2024 – at a phenomenal 22.6 percent CAGR.

Liquid-cooled servers have several inherent benefits from the energy efficiency viewpoint, attributable to their superior heat absorbent properties. Additional advantages include reliable deployment at hyper-scale operations, a significant reduction in overall TCO, silent operations with the elimination of IT fans, lower server power consumption contributing to minimizing carbon emissions.

Favourable design in liquid cooling servers has led to quick cooling features, robust component protection from overheating, optimal costs, and capability to withstand adverse conditions related to heat, dust, and humidity, irrespective of the location of the data center.

It is estimated that cooling equipment comprises a sizeable 20 percent of the capital investment for a greenfield data center. Air cooling mandates the use of CRAH and CRAC equipment and is based on the energy-consuming mechanical refrigeration principle. Liquid cooling, on the other hand, drastically curtails water usage by directly utilizing warm water aided by dry coolers, with superior cooling capacity and lower Capex and Opex for physical infrastructures.

The paucity of physical space, often, is a huge limitation for IT equipment and related cooling infrastructure. Liquid cooling can reduce the overall data center space requirements, by significant compaction features, for a certain IT workload demanding high implementation of GPU s like HPC environment, gaming software, etc.

Further, with the elimination of a hot or cold aisle arrangement, continuous sequential rows are possible, with room for layout manoeuvre. The liquid-cooled server has comparatively lower physical infrastructure needs with no need for a chiller, raised floors, or perimeter cooling system.

Augmenting a running data center with additional servers often brings about cooling and density bottlenecks. Since liquid cooling technology neither occupies RU space in the rack nor additional floor space, it does not strain existing infrastructure resources. Moreover, the dry coolers are conveniently placed outside the facility, saving on the floor space.

Even in harsh IT environments prone to dust and other contaminants, liquid cooling is a feasible option that disassociates the servers from the environmental impact and thus eliminates airborne dust. The waste heat recovered by the liquid cooling system may be profitably channelized for other heating purposes within the facility or premises in the near vicinity, positively impacting the overall operating cost savings.

From the perspective of sustainability, enterprises increasingly focussing on the power usage effectiveness (PUE), water usage effectiveness ( WUE) reduce energy & water consumption, and lower carbon footprint (CUE). Liquid cooling with its proven higher cooling efficiency in comparison to air-cooling can prove immensely beneficial in achieving these goals.

As storage density continues to rise, efficient cooling of storage is a challenge, aggravated by escalating costs. Liquid-cooled racks are well-equipped to handle dense high-performance computing and cluster installations scenarios from highly scalable enterprise-class data centres that cater to massive data volumes, high GPU and CPU applications, edge sites with limited availability of high-capacity power feeds to core applications with critical data-intensive workloads.

Liquid cooling facilitates the design of a sleeker cooling infrastructure for the data center and vice versa and enables handling a higher server density for a given volume of energy consumption.

The growing influx of new-age technologies namely cloud computing, AI, Big Data analytics, IoT, and edge applications driving the data boom, along with the growing clamour to optimize energy usage have paved the way for transformational change in the underlying, supporting cooling mechanism with an overwhelming preference for liquid cooling systems.

With the future trend towards green data centers, combined with intrinsic benefits like reduced water and energy consumption, it is just a matter of time before liquid cooling becomes the preferred, natural choice, for end-customers and EPC companies alike.
Sudipta Sanyal
By Sudipta Sanyal, chief technology officer, Data Center Business, Sterling and Wilson