Is it worth moving from an air-cooled data center to a water-cooled one?

One of the biggest challenges in the operation of data centers is provisioning the right level of cooling. This is an essential step. Cooling systems prevent server racks from overheating and becoming inefficient, or worse, conking out altogether.

Air cooling is the main method for cooling in data centers and advances in this space have helped maintain the efficiency and sustainability of data centers all over the world.

But for high-performance racks running the latest and most computationally-intense workloads, like frontier AI models, data center operators have turned to the superior heat transfer of liquid cooling systems.

While air cooling and liquid cooling come with specific pros and cons, a trusted server supplier like Dell Technologies can help leaders decide which is the best fit for their use cases and to pick the specific PowerEdge server that will unlock the most value.

Air cooling vs liquid cooling in the data center

For most data center cooling requirements, air cooling systems provide more than enough thermal regulation to keep systems running optimally. Specialized cooling fans run cold air over server components and generate airflow within the data center.

In Dell’s case, air cooling is available across a wide range of PowerEdge server options, pairing smart fan designs with passive cooling mechanisms in the racks themselves.

For example, the majority of Dell’s PowerEdge R-Series servers are air-cooled. These are workhorse server racks, packed with the latest Intel and AMD chips for core enterprise workloads, and they’re cooled in large part by fan systems.

Air-cooled systems are cheaper to build and run, and quicker to stand up. In turn, they’re quicker and cheaper to scale.

McKinsey and Company noted in a recent analysis of the data center market that there is significant potential for prefabricated and scalable component designs to greatly decrease the time it takes to construct or expand data centers, as well as improve site safety.

This is a major advantage of air cooling, as liquid cooling pipes in data centers take longer to construct and are harder to build out over time.

If your enterprise needs to run extremely high-density, high-performance workloads, like sensitive transactions in large volumes in parallel or AI inference at scale, liquid cooling might be a better option.

This is because even the best air cooling systems can struggle to maintain the temperatures of server racks running the most intensive workloads. McKinsey and Company noted that racks operating at a power density of 60kW or above are prime targets for liquid cooling.

TL;DR: air-cooled data centers are still the standard for core enterprise workloads and benefit from lower upfront costs and scalability. For frontier workloads and high-performance computing, meanwhile, innovative liquid-cooled designs are increasingly necessary.

What are the choices for data center cooling with Dell PowerEdge?

Dell PowerEdge has solutions to fit both data center architectures, depending on the needs of the customer.

While the PowerEdge R-Series is primarily designed for air cooling, a number are available as both liquid and air-cooled solutions. Similarly, the PowerEdge XE-series – Dell’s most powerful servers for intense data center workloads – are available in a range of different cooling configurations.

For example, servers such as the PowerEdge R7615 can be configured for air cooling, using Dell’s fans and smart cooling algorithms to keep all server components at the optimal temperature, or for liquid cooling.

Dell offers a broad liquid cooling portfolio, including direct liquid cooling (DLC) for the most intensive server racks, such as the PowerEdge XE9780L. In these DLC configurations, warm facility water--typically around 32 to 36 degrees Celsius (89.6 to 96.8 degrees Fahrenheit) circulates through liquid cold plates mounted directly on key components to absorb and remove heat.

All of these configurations are scalable, hot-swappable for maintenance without downtime, and monitored by smart sensors to keep operations running smoothly.

TL;DR: Dell has expertise in both air cooling and liquid cooling, and offers a wide range of PowerEdge configurations to meet the specific needs of its customers.

What makes Dell’s cooling stand out from the competition?

Dell's proprietary cooling fans help maintain tightly controlled temperatures inside PowerEdge servers, which in turn supports more stable and predictable thermal conditions in the data center. They combine PowerCool algorithms with telemetry from up to 70 sensors per server to adjust fan speeds precisely, delivering the airflow needed to prevent internal component temperatures from spiking while minimizing unnecessary fan power draw.

Because PowerEdge servers are fully compatible with the major operating systems and hypervisors, administrators can quickly and easily connect their systems to embedded PowerEdge tools. These include Integrated Dell Remote Access Controller (iDRAC), which gives IT teams remote access to monitor and manage individual server nodes, as well as to oversee thermal levels and cooling approaches.

In laboratory tests, Dell has demonstrated how its AI-based algorithms and power and fan controls can help improve data center performance and reduce costs in tandem. This includes ‘PowerCool’ configurations that can reduce or remove the need for liquid cooling in specific cases for data center CPUs.

That said, in some circumstances air cooling simply won’t be enough to maintain server temperatures – even with innovative approaches to fan speed. This is where Dell’s proprietary DLC methods come in, bringing the certainty of heat transfer via dedicated pipes that run next to the server racks.

In hybrid scenarios, data center operators can combine air cooling with solutions such as Dell’s PowerCool Enclosed Rear Door Heat Exchangers (eRDHx). These components draw hot air directly from the rear of server racks, cool it via an air-to-liquid heat exchanger, then recirculate the air to cool the racks.

It’s an efficient, proprietary system that enables air cooling to handle up to 80kW of energy demand per rack and unlocks a 60% overall reduction in energy consumption for cooling.

All of Dell’s PowerEdge cooling methods have been extensively tested in the real world and have demonstrated real value to large-scale enterprises.

For example the Indian payments platform PhonePe, which has nearly half a billion customers and processes more than 185 million transactions per day, relies on Dell PowerEdge servers to meet its operational requirements.

In its Mumbai data center, PhonePe has deployed Dell PowerEdge servers with Intel Xeon Platinum processors, cooled by DLC as well as some specialized racks submerged in dielectric fluid, a process known as liquid immersion cooling (LIC). This setup allows PhonePe to meet its service requirements at scale, without negatively impacting its carbon footprint.

As a direct result of the efficiencies unlocked by liquid-cooled Dell PowerEdge servers, PhonePe has cut its power usage efficiency (PUE) from 1.6 to 1.35 and saved more than$3 million per year through reduced power consumption.

“If you look at a server from a commodity standpoint, there are thousands of providers that can give you a server,” said Burzin Engineer, co-founder and chief reliability officer at PhonePe. “But to tie it cohesively together into an alternative cooling solution is where the Dell PowerEdge servers actually shine through. Dell PowerEdge servers are customizable to fit the specific requirements of PhonePe.”

TL;DR: Dell has a proven track record in delivering effective cooling solutions, with proprietary designs that keep servers running at peak efficiency and drive measurable cost savings at scale.

If you think PowerEdge R-Series servers are the right fit to give your business that streamlined edge, for US readers click here, and for CA readers click here to learn more.