Because of the record heat, English data centers have failed. Adrian Altenburger from the Lucerne University of Applied Sciences and Arts knows how such incidents can be prevented. But no one is listening to him yet.
Heat-sensitive devices: Cooling servers less could save energy and prevent failures.
A data center ensures that users can surf the Internet, stream films or access their cloud. But it also produces a lot of hot air. Because: The computers in the server cabinets work around the clock and heat up under constant load. So that they do not get too hot and suffer damage, they have to be cooled by efficient air conditioning systems.
In Great Britain, the first data centers had to be shut down last week due to record temperatures of up to 40.2 degrees Celsius because the cooling system could no longer keep up. The companies affected were Google and Oracle, which operate cloud services at locations near the English capital London. There were interruptions in the online services, as reported by several industry platforms.
Professor Adrian Altenburger works at the Lucerne University of Applied Sciences and Arts and has been working on the cooling of data centers for a long time. For him, the outages show that the energy used in data centers is inadequate.
Mr. Altenburger, it gets hot every summer. Why are data centers not better prepared for high temperatures?
Normally, the cooling systems in conventional data centers are designed in such a way that they run without problems up to an outside temperature of 32 °C. In individual cases, the tolerance may be 35 °C due to design reserves. But at over 40 °C it can be over.
What happens when it gets too hot?
Then the computers are shut down so that they can cool down. This is usually not a problem: all data is stored in more than one place. Users then access a backup without realizing it.
If it gets this hot more often in the future: doesn’t something have to change?
You will have to consider whether the previous systems are really as resilient as you thought. The problem is the temperature difference between indoor and outdoor air. The aggregates use the outside air as a heat sink, cool it down and direct the cooled air to the servers – this often with a supply air temperature of less than 20 °C at the server inlet. When it gets very hot outside, however, the cooling effort increases enormously due to the large temperature difference. And the systems are reaching their performance limits.
What do you suggest?
There are studies that show that data centers run without problems even with an air inlet temperature of 27 °C. They can also cool down to this temperature when it is very hot outside. In the USA, this was already defined in 2004 together with the IT industry. According to this recommendation, an operating temperature of up to 32 °C is permitted.
Data centers would therefore have to get warmer in order to be able to deal with heat better.
Exactly. Seen in this way, it is far too cold in most server rooms.
Why hasn’t the American standard caught on yet?
Because two worlds meet here. Two parties are usually significantly involved in the planning of data centers: IT experts and building technology engineers. In order for their equipment to run smoothly, computer scientists often demand unnecessarily low temperatures without being aware of what this means for the infrastructure of the refrigeration systems. The building technology planners then implement this because they often don’t know any better.
But a laptop still works at 32 degrees.
In any case, I don’t know anyone who puts their laptop in the fridge before using it. When it’s warm and you need a lot of power, the ventilation on the laptop also kicks in. It’s no different in data centers, if you disregard the dimensions.
Higher operating temperatures not only avoid server failures, but also save a lot of electricity.
Exactly. We have conducted studies showing that the efficiency potential is around 45 percent. So it would work with half the energy.
Do the operators not care about these savings?
So far, the level of suffering has obviously not been high enough. With the rising energy prices and impending power shortages, that should finally change. In addition, there are no legal regulations today. This is a second important reason why common practice has not changed. Just imagine: whoever builds a single or multi-family house has to provide all sorts of proof of energy efficiency. In the case of data centers with a good hundred times the energy consumption per square meter of server room, you can do whatever you want.
Are there no regulations in sight?
We are together with the SIA [dem Schweizerischen Ingenieur- und Architektenverein, Anm. d. Red.] and the Federal Office of Energy. However, the requirements for energy efficiency in buildings vary from canton to canton. So it will be a while before there are uniform framework conditions.
What actually happens to the waste heat from the data centers – could it not be used?
Unfortunately, most of the time nothing happens at all. As a rule, the warm air is simply released into the environment via cooling towers.
It could be fed into district heating networks, for example.
That’s the thing with district heating. A large proportion of the data centers are located in industrial areas, far away from buildings that require heat all year round. Leading the heat from there into the households often requires a disproportionately high cost for the pipe network from an economic point of view. In addition, a lot of energy would be wasted unnecessarily. However, if the distance and the losses could be limited, the potential of data centers as a heat source would be substantial.
How do you imagine that?
Data centers belong in the vicinity of housing estates or in the context of buildings with a year-round heat requirement, if possible.
What excites you about the idea of living next to a concrete block with no windows?
Admittedly, today’s data centers are not really an asset for the townscape. But if you and all your neighbors can heat with the energy from next door, you might see things differently. The waste heat from a single data center can assume enormous proportions. This means that entire districts or even communities can be supplied. One example is the Grünmatt settlement of the FGZ in Zurich. Or a swimming pool that has been heated in Uitikon Waldegg since 2008.