Advancements in waterless cooling arrive at a moment when water scarcity has emerged as a critical issue around the globe.
With growing recognition of the need to protect water as a precious resource, the development of efficient waterless cooling systems stands at the heart of global efforts to mitigate man-made environmental harm. As data centers and other industrial and energy actors face more scrutiny around their environmental footprint, innovative waterless cooling strategies offer a shift towards more responsible resource utilization.
In this context, advanced thermal engineering combined with smart operational models are enabling a number of alternatives capable of minimizing the impact of cooling processes on water resources. Let’s take a look.
What is waterless cooling and why does it matter?
The term waterless cooling covers a number of cooling techniques that put water conservation at their center.
As such, it includes both air-cooling techniques as well as a number of liquid cooling strategies that use synthetic fluids as alternatives to water (such as dielectric fluids) to dissipate heat. All these are able to replace conventional evaporative cooling methods, which require abundant and constant water withdrawal to provide cooling.
The need to devise efficient waterless cooling systems has gained importance as more and more attention is paid to the impact of industrial and energy-generation processes on water resources. With the rise of data centers, including the expansion of hyperscale data centers, and the rising energy and resource utilization required for their operation, such attention is also directed towards these infrastructures’ cooling and operation.
Key data over water consumption in such processes highlights the importance of developing waterless cooling solutions:
- While cooling for data centers is crucial for operation, certain options also represent a major source of water use. For instance, conventional, medium-sized data centers have been calculated to consume around 300,000 gallons of water per day, the equivalent of around 1,000 households, as published by NPR. Meanwhile, just in the US, two-thirds of data centers are developed in locations “already gripped by high levels of water stress” according to Bloomberg news.
At the same time, the rise of AI is expected to put an increasing strain on water use due to the growth in computing power requirements. For instance, entering 20 - 50 queries in prompt-based AI systems involve using half a liter of fresh water, as calculated by scientists in the University of California, Riverside.
- In the case of power generation, water usage for cooling purposes in electricity generation represents a major source of water withdrawal. For instance, in the US, 47.5 trillion gallons of water were withdrawn in 2020 for the electric power sector’s cooling needs, according to official sources. While this constituted a 2.1% decrease from the previous year due to the move away from fossil fuels, the quantities position electricity generation as a major player in water resource use. Meanwhile, in Europe, water abstraction for cooling in electricity generation represents “the largest contributor in the EU-27 to total annual water abstraction”, accounting for 34% of water withdrawals in 2022, according to official sources.
As water conservation becomes a key concern for both citizens and public authorities, it also evolves into a crucial aspect for industry and data center operators’ strategies.
What types of data centers can use waterless cooling systems?
Important advancements in thermal engineering are allowing data centers to move away from “open-loop” evaporative water cooling (which need abundant and continuous water intake) to waterless cooling alternatives.
Among these alternatives, the most prominent today include closed-loop systems, a model that can act as a viable retrofit for data centers of all sizes. The system reduces water intake because, once it’s filled, it doesn’t require ongoing refills. Additionally, it can enable the use of recycled water or rainwater harvesting, and has thus been described as capable of reducing freshwater use between 50-70%, as published by the World Economic Forum.
The following approaches to cooling are compatible with waterless operation:
- Liquid cooling, which includes:
- Immersion cooling: an advanced method for liquid waterless cooling that relies on submerging server components in specialized, non-conductive fluids, which achieve heat dissipation and replace water use. By directly addressing the source of heat and using fluids that are engineered for this specific purpose, immersion cooling provides a number of efficiency gains and energy savings, while also achieving uniform cooling and eliminating hotspots rapidly. In fact, this method has been described by ASHRAE as having “the benefits of broad temperature support, high heat capture, high density and flexible hardware and deployment options.”
- Direct-to-chip cooling: another advanced strategy for waterless cooling systems that relies on delivering synthetic dielectric fluids directly to server components. In this case, a number of cooling mechanisms are employed to directly remove heat from the chips, thus targeting the hottest components.
- Air cooling: this approach relies on a variety of airflow control techniques and heat dissipation equipment and can thus be mentioned as part of waterless cooling strategies. Current and prospective heat dissipation needs in servers surpass the capacities of air cooling, making it an option with limited scope, mainly for mild climates or small retrofits. However, employing air-cooled chillers can become a key ally in achieving waterless cooling outside data halls for certain data center locations with mild temperatures and minimal-retrofit projects.
- Free cooling: this method relies on employing cold ambient air for cooling down data center equipment. Particularly efficient in locations with cold climates, free cooling is being explored as a viable option for reducing energy-related costs in data centers.
When it comes to designing a waterless cooling system, this variety of approaches allows each data center to leverage diverse techniques according to each project’s own needs and potential.
On the one hand, liquid cooling models such as immersion and direct-to-chip systems present important efficiency advantages, as they are based on fluids’ outstanding efficiency as heat conductors when compared to air.
On the other hand, hybrid models are emerging that combine the advantages of different systems. Such is the case of configurations where servers are partially cooled by either immersion or direct-to-chip cooling, while the rest is cooled with air cooling systems. A configuration that is fully compatible with waterless designs, such as closed-loop circuits relying on air-cooled chillers. All of it aided by advanced, data-driven systems capable of optimizing operations in data centers.
You might be interested: What is liquid immersion cooling?
Key benefits of implementing waterless cooling systems
Water conservation and sustainability
Waterless cooling is aligned with current preoccupations around water usage in data centers, the industry and beyond, as well as tightening regulations related to this issue.
Organizations that opt for these systems showcase a proactive commitment to reducing their environmental footprint, thus accessing not only compliance benefits but also a competitive advantage.
Improved efficiency and thermal control
Advanced waterless cooling not only implies savings in water resources, but can also be designed to allow for important energy efficiency savings.
The strategies to achieve this vary depending on the waterless cooling method: some imply the incorporation of high-efficiency chillers; others are implicitly more efficient due to using techniques based on more targeted, faster and controlled cooling.
A critical move in the current context, where incorporating advanced cooling systems represents a strategic decision to improve ESG and gain operational advantages.
Regulatory and environmental compliance
As concerns around water usage and environmental responsibilities escalate, tightening compliance requirements are emerging across all industries. In this context, implementing waterless cooling marks a crucial step for guaranteeing compliance while also positioning projects as proactive in targeting their environmental impact.
Applications of waterless cooling systems across industries
Data centers and IT infrastructure
In data centers, waterless cooling allows operators to handle rising heat loads while also minimizing their water consumption, moving away from evaporative cooling models.
This can be critical for facilities in water-scarce regions, but also for all types of infrastructure looking to achieve operational advantages, as they gain more independence in water supply and minimize risks related to water shortages.
Industrial processes and manufacturing
A look at data around water use in industrial processes and manufacturing provides insights on the importance of taking steps towards water conservation. For instance, in the EU-27 countries, water abstraction for manufacturing and the industry has increased since 2010, according to official sources, with manufacturing representing the fourth largest water abstraction source in the EU, followed by mining and quarrying.
In this context, waterless cooling is also a major move towards more responsible resource utilization in industrial processes and manufacturing.
Energy sector: power plants and renewables
As mentioned above, cooling for power generation stands out as one of the most significant causes of water use around the globe.
More specifically, important water withdrawals can be traced back to thermoelectric plants based on coal, natural gas, and nuclear energy. For instance, in the EU-27 countries, water abstraction for cooling in electricity generation is the largest contributor to total annual water abstraction, with figures being larger than those of agriculture. Meanwhile, thermoelectric power plants represent the largest cause of water withdrawals in the US. The same US official sources also confirm how the move away from coal and in favour of natural gas and renewable energy sources is facilitating a decline in water utilization for cooling in energy generation. For instance, in 2021 coal-based plants averaged a water-withdrawal intensity of 19,185 gal/MWh, compared to 2,803 gal/MWh of natural gas and the use of no cooling water for wind and solar photovoltaic.
In this context, efforts to implement waterless cooling represent key movements towards more efficient and sustainable resource utilization. This is particularly crucial in the energy sector, where improvements can cascade across industries, enabling more sustainable operations throughout diverse economic sectors.
Challenges and considerations in waterless cooling adoption
Initial investment and system complexity
Waterless cooling systems represent an advanced approach to cooling, and some of these systems rely on cutting-edge thermal engineering. As such, the move towards waterless cooling often represents entering complex projects that require higher upfront investments compared to more conventional cooling options.
Infrastructure adaptations and upgrades, the addition of specialized equipment and piping, matters related to impermeability and material compatibility… A number of design decisions and best practices in implementation that demand embarking on intricate engineering processes guided by experts.
However, in successful design and implementation of waterless cooling, these initial constraints are counterbalanced in the long-term, as improved energy efficiency and advanced operations deliver their advantages.
Fluid selection and heat transfer performance
In waterless cooling systems such as immersion cooling and direct-to-chip cooling, the right choice of cooling fluid is essential, as it can promote greater thermal conductivity as well as ensuring equipment safety and longevity.
As such, the fluid’s thermal properties, safety and stability must be considered for successful projects, as well as its environmental profile and its compatibility with the system’s components.
Future outlook: is waterless cooling the new standard?
As seen across the article, waterless cooling is not a mere trend, but a transformative response enabling entire industries and sectors to respond to global environmental and operational challenges.
This shift towards more responsible resource utilization represents a structural adaptation towards solving a number of difficulties that will need to be navigated in the coming years: from addressing water scarcity to guaranteeing resilience and meeting regulatory measures.
As attention over resource utilization grows more rigorous, cooling turns into a major design priority capable of future-proofing operations. Meanwhile, the operational and efficiency benefits of advanced cooling solutions described above also point towards waterless cooling becoming the new standard for the immediate future.
In this context, at ARANER we are committed to helping companies leverage advanced cooling technologies today that build the competitive advantage they seek.
Through our cutting-edge thermal engineering solutions for data center cooling, we are allies for data centers looking to build the waterless cooling system that aligns with their project’s needs.
Get in touch with us and learn how we can help you.
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