Data Center Liquid Cooling – A Hot Trend
There is no denying it, liquid cooling in data centers is hot right now. Traditionally, air has been used to cool data centers, including IT equipment, server racks, and general room air. And, while it has been effective, even with many different hot/cold containment strategies, it is not the most energy efficient option. For this reason (and others!) liquid cooling is gaining quite a bit of traction in the technology industry.
Power Density Increases & So Does Need for Effective Data Center Cooling
Data size is rapidly growing and thus power density is dramatically increasing and that means cooling needs have shifted significantly. One of the main problems with air conditioning is that it can be more difficult to scale – it simply is not the most flexible cooling option. Data Center Journal explains the need for energy efficient and cost effective data center cooling options, “In 2016, GMI reports, about $8 billion was spent worldwide on data center cooling. By 2024, that number is expected to reach $20 billion. With equipment power consumption accounting for about 40% of a data center’s energy usage, the need for cost-effective and energy-efficient solutions has never been more important. Optimum cooling is essential to prolonging the life of hardware and increasing performance, but the solution must also be financially viable for data center operators…When comparing cost, it’s often an apples-to-oranges analysis because the two cooling approaches have different needs. For example, liquid cooling uses either water or a manufactured liquid, but the water must be filtered for contaminants. Certain maintenance costs, such as ongoing water treatment, must be factored into the operation of liquid systems, but the energy costs are less and the liquid is more efficient and cools the air faster than air. Since water and air have different densities, a line-by-line comparison is almost impossible. But more data centers are eyeing the advantages of liquid cooling as a way to reduce waste, costs and their carbon footprint.”
As rack density grows, so do cooling demands. Most typical air conditioning systems will have to undergo significant overhauls or be replaced completely to accommodate the cooling needs of such high rack density. While it is hard to scale air conditioning systems to meet the needs of higher rack density, liquid immersion cooling can scale much more easily to meet demand. Further, the coolant used can tolerate and absorb heat very well so racks can be packed more tightly, allowing for maximized rack density which saves space.
A Closer Look at Immersion Cooling in Data Centers
As fears of water damaging electronic components through leakage or some other disaster, immersion cooling has gained popularity. Server racks are safely immersed in special coolant fluid that is non-conductive and non-flammable to help keep them cool in a more efficient way and it is safe for the equipment. There are two types of immersion coolants used – two-phase and single-phase. While leaking can occur, it is more likely to occur with two-phase coolant than single-phase coolant, as Data Center Knowledge explains, “To choose the best system for your data center, the most important distinction to keep in mind is the type of coolant used for immersing server components in liquid: single-phase or two-phase. The two phases of a coolant are liquid and gas. A single-phase coolant remains a liquid and is pumped to a heat exchangers to remove the heat. A two-phase coolant is one that changes from a liquid to a gas at low temperatures. When immersed in two-phase coolants, a server creates heat sufficient to cause the coolant to boil off as a gas. This gas is then captured by a condensing system that turns the gas back to a liquid. Otherwise, just like boiling water, eventually there would be no liquid left…Single phase coolants do not change phases and do not evaporate in air, like two-phase fluids. They are an order of magnitude lower in cost than two-phase coolants. And, because single phase coolants don’t evaporate in air, the system does not have to be sealed to ensure evaporating liquid is recaptured. This also makes it easier to remove or replace server components and improves the serviceability of the system…With single-phase fluids, the data center environment is improved – it is quiet and a comfortable and consistent temperature throughout. Servicing is easier because the servers are at waist height, and they can be removed or replaced to repair them in the rack without having to move to a workbench for servicing. Additionally, the airflow in the data center does not need to be reconfigured to add or delete servers from racks.”
Should Data Centers Convert to Immersion Cooling Now, Rather Than Later?
Data is rapidly growing, but how big of a concern should it be for data centers? Should they convert to immersion cooling not just to improve energy efficiency now, but also when increased power density demands increased cooling. Forbes notes just how rapidly data power consumption is growing, “U.S. data centers use more than 90 billion kilowatt-hours of electricity a year, requiring roughly 34 giant (500-megawatt) coal-powered plants. Global data centers used roughly 416 terawatts (4.16 x 1014 watts) (or about 3% of the total electricity) last year, nearly 40% more than the entire United Kingdom. And this consumption will double every four years.” By converting to immersion cooling you can consume less energy for cooling and make your data center far more energy efficient.
It is undeniable that there will be a time when every data center with traditional air conditioning will have to reevaluate their cooling methods to improve efficiency. There are a variety of options to cool data centers, but immersion cooling offers some distinct advantages over other methods, particularly when dealing with high-density power consumption. Many industry estimates put cooling costs at about 40% of a data center’s energy consumption. Immersion cooling may be able to reduce a data center’s energy usage by over 60%, with some systems stating it could be as much as 95%! For many data centers, that is millions of dollars in savings every year.
Is Immersion Cooling the Future of Energy-Efficient Data Center Cooling
The future is coming quickly and that means huge data will be here sooner rather than later. And, with huge data comes a major demand for more energy-efficient and effective data center cooling. Immersion cooling meets the needs of an ever-growing data center power density and will likely. While the fear of mixing water and electronic equipment (an obvious no-no) was the primary reason for not adopting a liquid immersion cooling system in the past, new systems have become much safer and more effective at protecting critical electronic equipment from damage. Because of the effectiveness, energy efficiency, and cost savings liquid immersion systems have to offer data centers, it is likely going to be one of the most popular cooling technologies to meet the data demands of the future.
