Issue link: https://www.e-digitaleditions.com/i/1464345
56 I ICT TODAY With two-phase immersion cooling, the liquid is first boiled and then condensed. Electronic compo- nents are immersed in dielectric liquid, just as they are in single-phase immersion cooling, but as the heat from the electronic components rises, the fluid boils and then vaporizes. As the vapor condenses on a heat exchanger, heat is transferred to the facility's water system and flows out of the data center. For fans, typically constrained by the equipment enclosure's form factor, there are limitations to how much airflow they can generate while meeting the acoustic and efficiency requirements. The constant whirring of fans spinning at top speed, working to keep the data flowing, is clearly audible in a data center. This constant performance strains the equipment and pre- vents fans from serving as the single solution. The reality becomes clear—it has reached the maximum capacity of an air cooled only approach for today's applications. Therefore, one must rely on alternate approaches, such as liquid cooling and immersion cooling. However, liquid cooling can be more costly in some scenarios where more power is needed. Immersion cooling offers a lot of potential to move large amounts of heat away from one equipment enclosure or multiple equipment enclosures in a small space. IMPORTANT CONSIDERATIONS FOR DATA CENTER COOLING Factors such as physical location, energy access, environmental elements, government regulations, and appropriate rack configuration are all important consid- erations when determining the optimal approach for any data center build-out or upgrade. For new data centers, the physical location is clearly a serious consider- ation. Energy access impacts how much it will cost to run the data center. Environmental elements play a pivotal role in determining what weather conditions will add to the cost of keeping the data center cool. Immersion cooling has become increasingly popu- lar recently thanks to the sustainability initiatives by hyperscale data centers that include carbon reductions, renewable energy, and carbon offset. Immersion cooling reduces the carbon footprint of the data center by an estimated 15 to 30 percent. Location and the ability to reuse the wasted heat play into the total sustainability benefit, making immersion cooling a key consideration for data centers aspiring to be more sustainable and eventually achieve net-zero carbon dioxide emissions. While this method of cooling has been around for decades, it has not deployed at scale due to a number of complexities. Data center professionals and engineers are working to navigate the thermal specification for their equipment enclosures and systems, as well as making decisions about their supply of voltage possibly moving from 12 V to 54 V. It is also important for data center professionals to understand how this impacts overall power efficiency. These conversations can lead to customized options to spread out the heat more uniformly throughout each equipment enclosure, as well as the entire data center, making everything more efficient. LIMITATIONS TO EXISTING COOLING METHODS Data center professionals and engineers are working to navigate the thermal specification for their equipment enclosures and systems, as well as making decisions about their supply of voltage possibly moving from 12 V to 54 V. The physical limitations of existing air-cooled solu- tions, given increases in power density, often require significant changes to traditional data center archi- tectures. While rack and cabinet sizes do not often change, space utilization is becoming increasingly more important. Data center architects are interested in adding as much computation as possible into as tight of a space as possible. With more components to cool, the limitations of existing cooling options become very apparent.