Is Liquid Cooling Right For Your Data Center?

We live in an exciting time—liquid cooling, which once seemed more trouble than it’s worth, is fast becoming an accepted and sought-after technology in the data center industry. That said, it’s still a complex technology to implement, especially in legacy facilities. Is your data center ready to operationalize liquid cooling?

Liquid cooling in the data center

Liquid cooling in the data center is just that—cooling technology that uses liquid to remove heat from the chip without using air as an intermediary. There are several types of liquid cooling that are popular in the data center industry, but for a quick overview, the three main categories can be grouped as follows:

• Direct liquid cooling – cooling technology that exposes server components to liquid to remove heat
• Air-assisted liquid cooling/hybrid liquid cooling – cooling technology that uses a combination of air and liquid to remove heat
• Liquid immersion cooling – cooling technology that submerges server components into liquid to remove heat

These technologies can be implemented using single-phase or two-phase fluids. Single-phase fluid stays liquid for the entire process, whereas two-phase fluid becomes a gas during the cooling process. Single-phase fluid is more commonly used because a two-phase implementation can be more complex. However, given the potential efficiency that two-phase fluids present, there is a growing body of research on the topic that may envisage smoother implementation and wider use in the future.

The main reason to consider implementing liquid cooling in your data center is if you are encountering rising power densities and heat generation. High-density designs, increasingly compute-intensive workloads, and server rack densities are slowly but steadily rising. Air cooling is sufficient for capturing the heat flowing from servers at densities below 20 kW; however, when rack densities exceed 20-25 kW, direct liquid cooling combined with precision air cooling has been found to be more economical and efficient. To overcome the continued increase in heat generation, and potentially save energy and money in the process, liquid cooling might be a practical solution for many facing high-density or mixed-density designs moving forward.

How to test liquid cooling in the data center

Computational fluid dynamics (CFD) is a science that uses computers to produce quantitative predictions of fluid-flow phenomena based on the conservation laws (conservation of mass, momentum, and energy) governing fluid motion. CFD simulation is widely used across various industries, including aerospace, oil/gas, automotive, and electronics, to make critical design decisions. Within the data center industry, CFD simulation is used to predict airflow and temperature distribution.

CFD simulation software can be used in both design and operations to make informed, data-driven decisions. Cadence data center software creates a digital twin, or virtual replica, of the data center that can simulate the data center’s physical operations under any working conditions. Specifically, in the case of liquid cooling, Cadence data center software can virtually test how liquid cooling will operate in your data center.

Liquid cooling is intricate enough that solely solving in a 3D model could be computationally excessive. Cadence software connects the 3D model with the 1D network—a feature unique to our software—which makes for quick solve times and easy thermal analysis. By connecting these two, our software cuts down on grid cells and, therefore, solve time.

It is important to note that Cadence data center software can determine the heat capture ratio as well. To obtain the heat capture ratio, or the ratio of heat that was picked up by liquid over the total heat, Cadence data center software uses the static pressure drop and thermal resistance curves of cold plates, which can be obtained from their detailed CAD model. After completing the IT level analysis, the IT model can be used in the rack level model, and in turn, the rack level model can be used in the digital twin model to complete the solve.

Implement liquid cooling in your data center with confidence

Is your data center capable of handling a variety of heat rejection systems? What would liquid cooling implementation look like in your data center? CFD simulation software offers a clear framework to validate and implement liquid cooling in your data center. Learn more about Cadence data center solutions.