With our ever-increasing reliance on data storage and access to keep businesses running, particularly in critical times, the energy demands on data centers are predicted to grow exponentially in the years ahead. Currently, according to the U.S. Department of Energy, there are three million data centers in the U.S. using, collectively, 73 billion kWh in electricity. The electronics and electrical equipment inside data centers generate a significant amount of heat while operating 24/7/365; effective cooling is critical to keep data center systems running and prevent downtime.
With processing power increasing, the demand for cooling will only increase. The pressure is on engineers to develop better ways of cooling. Not only do they have to design for increased operational efficiency and reduced power consumption, but they also must design for decreased carbon emissions from data center operations. Adding to those challenges: data center cooling systems need to function at low and high IT loads as well as a variety of ambient conditions, depending on geographic location.
Current trends in data center cooling
The green transition is accelerating the move toward sustainable data centers, as measured by power usage efficiency, carbon usage efficiency and water usage efficiency. Cooling systems will need to become more efficient and reduce their carbon emissions, adopting electric heat sources such as heat pumps instead of systems that use fossil fuels. With the approaching phasedown of HFC refrigerants, low-GWP refrigerants such as R1234ze will become the standard. Danfoss has developed compressors, flow controls and heat exchangers to work with the new refrigerants.
New and innovative cooling techniques are being developed to meet the demands of data centers. Free cooling uses either cool outdoor air or water available in the area (from a lake, river, etc.), to provide cooling through gasketed plate heat exchangers and other components. There are also evaporative and adiabatic cooling techniques, that work in conjunction with Danfoss high pressure pumps, misting modules and variable-speed drives and fans. Variable-speed technology is very useful to data centers since, even though cooling is needed 24 hours a day, the load profile changes depending on time of day and season.
Power density in data center server racks is increasing as the demands on IT technologies and internet services increase. Data centers are growing across every dimension: smaller, edge data centers; modular data centers which require deployment speed and mobility; large enterprise and colocation sites; and hyperscale sites. Each site has its own cooling infrastructure needs, whether self-contained, CRAC units or large chiller plants, and those needs change over time. Data center operators and consulting engineers will need to continuously reevaluate and rewrite cooling specifications to meet the cybersecurity guidelines, uptime, and decarbonization levels that customers expect.
