This is an excerpt from an article featured in ATMOsphere’s “Clean Cooling for Data Centers 2025” report, which can be downloaded here. ATMOsphere is the publisher of NaturalRefrigerants.com.
BAC is a global manufacturer with more than 85 years of experience designing and producing heat rejection technology for the HVAC&R industry. Headquartered in Jessup, Maryland, BAC serves a broad range of applications, including central air-conditioning, commercial and industrial refrigeration and process cooling.
The company operates 10 manufacturing facilities worldwide, enabling it to supply and support projects across the Americas, Europe, Africa and Asia. In the past 15 years, data centers have emerged as a distinct and rapidly growing vertical for the company, according to Jan Tysebaert, Global General Manager for Data Center Cooling at BAC.
BAC’s data center solutions range from evaporative cooling towers to dry coolers that use no water as well as hybrid systems that combine both technologies. The company also manufactures custom-built coils used in air-cooled chillers and computer room air-handling (CRAH) units. With the rise of high-performance computing, BAC has expanded its offerings to include equipment for liquid-cooled systems.
BAC’s COBALT immersion cooling system combines the company’s outdoor heat rejection equipment with patented immersion cooling tanks to create a complete end-to-end cooling solution, Tysebaert said. Unlike conventional single-phase immersion systems, BAC’s immersion cooling tanks – powered by CorTex technology – feature an in-tank heat exchanger that is fully immersed in the same dielectric fluid as the servers. This design eliminates the need for a separate coolant distribution unit, keeping the dielectric fluid entirely contained within the tank.
“At BAC we believe that single-phase is not only the most practical and the safest type of immersion cooling but that it is also the most efficient solution,” noted Tysebaert.
This integrated design creates a reliable, simpler and more compact system that minimizes the risk of cooling fluid leaks, reduces cost and saves space in the data hall, Tysebaert explained.
BAC’s immersion tanks
Each tank can accommodate up to 48U (rack units) of servers and supports various configurations for 19- and 21-inch (48.3–53.3cm) server racks, allowing data centers to maximize rack density. With the use of the CorTex technology, the tank’s dielectric fluid circulates upward across the servers, efficiently absorbing heat before being recirculated through the integrated heat exchanger, which is designed to ensure uniform cooling and stable operating temperatures.
By delivering the entire cooling chain – from immersion tanks in the data hall to evaporative or dry coolers outside – operators can achieve maximum free cooling potential, according to BAC. In many climates, this design can eliminate the need for mechanical chillers entirely, reducing energy use and maintenance costs while simplifying the system architecture, according to the company.
“Immersion cooling will ultimately prove to be the more efficient, sustainable and scalable long-term solution.”
Jan Tysebaert,
Global General Manager for Data Center Cooling at BAC
Most high-density data centers – where liquid cooling provides the greatest efficiency gains – currently favor direct-to-chip (DTC) technologies, according to Tysebaert.
“Today, most applications use direct-to-chip cooling, which is largely being driven by server OEMs,” he noted. “They are making servers that are specifically designed for direct-to-chip cooling, which are a little harder to convert to immersion cooling.”
From the server OEM perspective, DTC is the more familiar and readily integrated option. However, from a cooling and facility standpoint, it presents significant design complexity and an increased risk of refrigerant leaks. In contrast, immersion cooling offers what Tysebaert said is a simpler and more streamlined solution, with refrigerant eliminated from the cooling system. In addition, he added that IT hardware OEMs are constantly introducing new solutions to ensure material compatibility and chemical resistance.
“Immersion cooling will ultimately prove to be the more efficient, sustainable and scalable long-term solution,” Tysebaert said, noting that BAC is collaborating with OEMs to develop server designs optimized for the technology.
Data center work to date
BAC has provided data center cooling solutions for more than two decades and entered the industry at a time when air cooling was standard. By the late 2000s, the company began working closely with hyperscaler and colocation providers to implement next-generation cooling strategies, such as economization, hybrid systems and free cooling. The industry shift toward liquid-cooled high-density computing increases demand for fluid-based cooling and free-cooling-optimized systems, areas in which BAC has longstanding expertise.
“Our decades-long experience in large-scale central cooling systems allow us to provide guidance and customization that go beyond equipment,” Tysebaert said. BAC has supplied cooling systems to more than 1,000 data centers worldwide, delivering thousands of units annually to colocation facilities and edge sites.
