As we try to keep up with the latest trends, we sometimes stumble upon a real gem in industry trends. The cooling demand of data centers and server parks is not a new problem, but the increase in cooling demand is huge. In this article, we present cooling best practices from recent years and also provide an insight into what the future may hold for data centers. Let us treat you to some specialities from the industry!
How has the cooling demand for data centers changed?
If we look at the layout of server rooms over the last 10-15 years, we don’t find much change in the power density of servers. For a long time, it was enough to air-condition server rooms, operating CRAC, that is, using a machine room cooling system to offset the heat coming out of the servers. These systems worked well as long as the servers did not convert more than 130 W into heat.
In recent years, however, the density of server power per shelf has far exceeded current standards, which has brought about the need to develop entirely new cooling solutions.
What is causing this huge cooling demand?
Artificial Intelligence (AI), increasingly popular esports and gaming, high-performance computers, 3D graphics, and the Internet of Things (IoT) all require faster and more complex computers. Just think of the explosive spread of cloud services, where providers are already competing for customers, forcing them to make the most of available space in their data centers. Of course, this increased power is reflected not only in the cooling demand, but also in the amount of electricity consumed. According to IDC statistics, the electricity consumed per server is growing by an average of 9% per year globally.
Continuous management of cooling of a data center lined up with such high-performance servers is also a challenge. Setting up a data center is preceded by a very thorough thermal design to optimize the required cooling needs. If the layout is not right, it can cost huge amounts to maintain safe temperatures. Experts must then continuously monitor the safe operation, power and heat consumption of servers and energy efficiency of the entire center so that they can intervene immediately if necessary.
How is a data center cooled?
In recent years, the physical separation of cold and warm air has become widely used, which can save significant energy. The point is to place a physical barrier between the fresh, cold air that the servers draw in and the hot air coming out of the servers, thus preventing the two from mixing. Another cooling method for the air is heat removal on the shelves, where the compressor and the chiller are installed in the shelves.
Since 2018, we have also seen a dramatic increase in the power density of servers, meaning that it is common to line up better, more powerful computers side by side. These high-performance data centers are pushing the boundaries of air cooling. On the one hand, air cooling systems will not be able to meet the exponentially increasing cooling needs; on the other hand, their operation will not be economical. Experts say cooling the chips with liquid may be the right solution.
What to expect in the future?
Developments are being made in two main directions to cool the chips. On the one hand, with plates placed directly on the processors, which dissipate heat. With cold liquid coming from outside, which is heated by hot servers and either leaves in that form or gives off heat by evaporation. Water would be evaporated in two phases with another insulating liquid. The other, much more futuristic method is to dip the entire hardware into a dielectric fluid. Of course, this is only the future, the cooling of server parks is still done with air cooling for the time being.