Liquid Vs Air Cooling: Which One You Should Choose To Keep Your Data Center Cool?

Liquid Vs Air Cooling: Different Types

Before comparing Liquid vs Air cooling, it is important to look at the types of air and liquid cooling.

3 Types of Air Cooling

Here are three different types of air cooling.

• Perimeter Computer Room Air Cooling

Perimeter Computer Room Air Cooling systems are a traditional method of air cooling where cool air is supplied along the perimeter of the data center. This method is simple, scalable, and easy to maintain. However, it may be less efficient compared to other cooling solutions, leading to uneven distribution of cool air, especially in large data centers. Additionally, it requires more floor space compared to alternative cooling methods.

• Perimeter Computer Room Air Cooling With Raised Floor Containment

Building on the basic Perimeter Computer Room Air Cooling system, the addition of raised floor containment aims to improve efficiency. This setup uses barriers and containment systems to isolate hot and cold air streams, preventing them from mixing. This approach enhances cooling precision and ensures a more consistent temperature throughout the data center.

• Row-Based Cooling With Containment

Row-based cooling with containment involves the use of dedicated cooling units positioned within rows of server racks, typically mounted overhead or under the floor, according to IDC. Containment strategies are employed to segregate hot air from cold air, enhancing cooling efficiency and lowering energy expenses. The approach offers benefits such as improved cooling efficiency, decreased energy costs, and a reduced risk of hot spots. However, drawbacks include higher initial costs, increased system complexity, reduced space utilization, and a heightened risk of condensation.

3 Types of Liquid Cooling

Here are three different types of liquid cooling options you can use to keep your data center temperature in check.

• Direct to Chip Cooling

Direct to Chip Cooling (DtCC) is a cutting-edge thermal management technique that revolutionizes traditional server cooling systems. Unlike conventional methods that rely on air-based cooling, DtCC involves the circulation of a liquid coolant in direct contact with the server’s processing units, such as CPUs and GPUs. This intimate interaction with the heat-generating components allows for highly efficient heat absorption and transfer, ensuring optimal temperature control within the server infrastructure.

The liquid coolant used in DtCC is specifically designed to have superior thermal conductivity, enabling it to rapidly absorb the heat generated by the processing units. As the coolant flows through channels or microchannels integrated into the server, it directly captures the heat at its source. This immediate contact facilitates faster heat dissipation compared to air-based cooling systems, where the heat must traverse various layers before being expelled.

One of the primary advantages of DtCC is its ability to maintain a more uniform temperature across the entire processing unit, preventing hot spots that can adversely affect performance and longevity. Additionally, this direct cooling approach enables servers to operate at higher power densities without compromising reliability or efficiency.

• Immersion Cooling

In immersion cooling, your technology infrastructure, whether they are servers or other equipment are all submerged into a specialized liquid which is dielectric and non-conductive to electricity. According to IDC research, immersion cooling offers unparalleled heat dissipation capabilities, but its implementation demands substantial modifications to server technology and data center architecture. 

While it allows for high power densities within data centers, the method entails complexities in both setup and maintenance, making it a radical departure from traditional deployment methods and incurring high upfront costs. Despite the potential benefits, the IDC underscores the challenges associated with immersion cooling, emphasizing the need for server modification and the complexity of its implementation and upkeep. 

• Air Assisted Liquid Cooling

Air-assisted liquid cooling (AALC) is an innovative approach to enhance traditional air cooling in data centers. In this method, liquid-filled radiators are integrated into the rear of data center racks to augment air cooling capabilities. Chris Sharp, the Chief Technology Officer at Digital Realty, highlights that air-assisted liquid cooling allows for the deployment of higher power densities, surpassing the typical 35 KW limit of air-only configurations and reaching up to 70 KW. 

Despite the increased cooling efficiency, air-assisted liquid cooling avoids the need for significant modifications to an organization’s existing equipment, providing a middle ground between air-only cooling and more complex direct liquid cooling solutions. Direct liquid cooling, on the other hand, can efficiently handle power densities exceeding 100 KW, making it particularly suitable for extremely dense racks, such as those used in high-performance generative artificial intelligence (AI) applications. 

However, this method introduces greater operational and deployment complexity. Data center operators must facilitate the delivery of liquid to the racks, and customers must possess compatible equipment with heat blocks attached to components generating heat within their servers. While direct liquid cooling offers unparalleled cooling capabilities, its complexity may limit its widespread adoption compared to the more accessible and versatile air-assisted liquid cooling.

Liquid Vs Air Cooling: Which One Should You Choose?

Arno van Gennip, Vice President of Global IBX Operations Engineering at Equinix, emphasizes the limitations of air cooling in data centers, particularly as new processors demand increasing power. With the growing inadequacy of air cooling for certain applications, liquid cooling technologies, including liquid immersion and direct-to-chip liquid cooling, are gaining prominence. 

Equinix observes a resurgence of interest in liquid cooling due to its superior heat transfer efficiency compared to air, making it a compelling solution for supporting high-density data centers amid the escalating power requirements of modern processors.

Liquid Vs Air Cooling? Which one would you choose for cooling your data center, and why? Share it with us in the comments section below.