Immersion Cooling: Single Phase or Two Phase?

Demand for data-intensive web services continues to skyrocket. In the United States alone, demand—measured by power consumption to reflect the number of servers a data center can house—is expected to reach 35 gigawatts (GW) by 2030, up from 17 GW in 2022, according to recent analysis from McKinsey & Company.

To meet these demands, data center managers are tasked with delivering exponentially more computing power. But as computing power increases, so does the heat generated by next-generation servers—and the right cooling technology is required to maintain optimal operating conditions.

It’s against this backdrop that immersion cooling—a breakthrough technology which submerges IT components in a non-conductive dielectric fluid—is gaining momentum as a game-changer for data centers. Some of biggest names in tech are taking advantage, and demand is only growing.

Two types of immersion cooling systems are in use today: single-phase and two-phase. Both methods involve fully submerging hardware in fluid, but each approach is significantly different—and for data center managers considering adopting this technology, it’s worth exploring those differences. Let’s take a closer look:

Data Center Cooling: Different Approaches to Meet Common Goals

First, it’s worth taking a step back to evaluate exactly what you need from your cooling system.

No matter the setup, your cooling system should contribute to:

• Operational efficiency. Your cooling system should make efficient use of the power it requires. Traditional air-cooling setups tend to be power-hungry, and usage can spike when weather temperatures soar. Immersion cooling systems can be more efficient, allowing facilities to divert more kilowatt consumption directly to hardware.
• Resiliency. Your ability to adapt to changing conditions is critical, and your cooling system plays a role in it. Data centers need optimal cooling solutions to provide continuous service for the lifetime of your server systems. Cooling-related failure can lead to costly downtime for your operations and outages for your customers.
• Longevity. Getting the most from your existing IT infrastructure is critical, and your choice of cooling has an impact. Optimal operating temperatures helps prevent thermal degradation of server components.

Immersion cooling solutions have the potential to help you achieve these goals and more. But not all of them are created equal.

Single-Phase Immersion Cooling

In single-phase immersion cooling, hardware is submerged in a dielectric fluid that makes direct contact with the IT equipment, conducting heat away as the fluid flows through a heat rejection mechanism. Organic or halogenated fluids may both be used in this application, although the latter are typically associated with higher cost and a less favorable sustainability profile.

Two-Phase Immersion Cooling

In two-phase cooling, a fluorocarbon-based fluid readily boils when in contact with equipment hot spots, transitioning the fluid from a liquid to a vapor that can be condensed in a heat exchanger and recirculated into the cooling tank. This phase change of liquid to gas allows the fluid to draw large amounts of heat from the equipment, but also requires integration of system design elements to facilitate the transition and a sealed system to prevent costly fluid loss from evaporation.

Advantages of Single-Phase Fluid Tailoring

Both single- and two-phase immersion cooling can help data centers achieve enhanced power density, better thermal performance, greater power usage effectiveness, and extended equipment life. Those benefits are reason enough for forward-thinking data center managers to strongly consider the technology, no matter the specifics.

But single-phase systems present some unique advantages versus two-phase. Perhaps most importantly, single-phase systems allow for tailored cooling fluids, enabling the formulation to meet data-center-specific needs. For example, copper is prevalent in server systems—and it’s particularly susceptible to corrosion when exposed to oil or water. This makes corrosion protection a critical characteristic for immersion fluid liquids. Your solution provider should be able to formulate your fluid with the specific chemistries required for long-term corrosion performance.

Fluid durability is another important factor. Your fluid should last the life of the server system in an optimal scenario. This eliminates the need for regular fluid changeouts, a maintenance task that can be both costly and time- consuming. And as power demands increase, specifically tailored fluids should be able to help extend the useful life expectancy of the hardware.

Immersion cooling’s advantages can be beneficial for data centers of any size, from more modest enterprise data centers to boundary-pushing hyperscale data centers. Smaller operations looking to get more from their current infrastructure can benefit from eking out more power density with immersion cooling. Hyperscalers, meanwhile, can deploy immersion cooling to maximize computing power even further.

Interested in learning more?

CompuZol™ immersion cooling fluid solutions from Lubrizol  are single-phase immersion cooling systems that can help take your data center operations to the next level. Taking full advantage of single-phase system architectures, our experienced fluid engineers work to tailor CompuZol fluids for optimal performance in a range of critical areas, including corrosion protection, longevity, and, of course, thermal performance.

Forward-thinking data center managers can’t afford to rely on legacy cooling technology as data demand continues to grow. Contact your Lubrizol representative to find out how CompuZol can transform your operations.