"Estonia has many server rooms that have fallen behind the times." How to get "in shape" for a hot summer?

Do you still remember last summer's heatwaves? While beach holidays here get ever more pleasant, high temperatures threaten the most business-critical part of our digital society: the infrastructure and IT systems on which the digital state, banking, all manner of cloud services, applications, e-commerce and so on are built.

In July last year, heat of more than 40 degrees knocked out Google's data centers in London: the cooling systems proved no match for nature, and among other things the outage affected websites hosted on WordPress across Europe. A September heatwave hit Twitter's data center in Sacramento on the US west coast in a sore spot. Inside the company the incident was called "unprecedented": the heat knocked out the entire physical plant.

If even data centers designed specifically for housing servers cannot withstand heatwaves, you can only imagine what it means for those who keep servers on their own premises, in an office building for instance, where suitable conditions are not guaranteed. "Estonia has many server rooms and buildings whose solutions have fallen behind the times. That is felt especially in the light of rising energy prices," says Allan Suurkask, CEO of BVT Partners OÜ, which sells ventilation and cooling equipment.

Is there reason to fear heatwaves in Estonia too?

Estonia's heat record dates from 1992, when 35.6 degrees was measured at the Võru station. The past two summers were also exceptionally hot here: the summer of 2022 was the second warmest of all time. According to the Environment Agency, two longer heatwaves reached Estonia, with three in total in southern Estonia. Only the summer before, 2021, was hotter than last summer.

Tõnu Grünberg, head of Greenergy Data Centers (GDC) in Hüüru on the edge of Tallinn, the data center with the most powerful cooling in the Baltics, warns that climate change, which we feel most sharply here as summer heat, threatens above all servers located in office buildings with modest cooling and in older data centers. An ordinary office building is simply not designed for such a load, and as a rule the cooling is not duplicated either, so if the equipment shuts down due to overload, that is that. Older data centers in turn may struggle with newer equipment, and there is also a risk in tired cooling units at the end of their life cycle.

"Compared with general construction, for example, the IT sector is a very young and evolving part of building. Solutions that were good 10 to 15 years ago are outdated today. And that is not only Estonia's problem," Suurkask explains. "But much sadder than the existing server rooms is when new or renovated projects do not get good solutions either. Estonia is small, and unfortunately experience and knowledge accumulate slowly here. Because of the small market there are few specialists who could dedicate themselves solely to the cooling and climate systems of data centers and servers," says the head of BVT Partners.

Even global big names are not ready for heatwaves

Data centers are an inseparable part of our digital society. Everything we do online physically lives in equipment and servers kept mainly in data centers. Servers need a cool temperature to work, which is why heat is their greatest enemy. Equipment that receives, processes and transmits data generates heat as it works anyway, so a heatwave is like pouring oil on the fire.

"First, there is certainly a threat to the most important thing, the reliability and longevity of the servers. The second big problem is energy cost, and here it can be said with a clear conscience that a great many people do not realise how much energy goes to waste because of old or poorly designed cooling systems," Suurkask explains. "It is a common situation that a cooling system is built at the outset that is too powerful and therefore inefficient. Over time servers are added and the cooling system can no longer provide the necessary conditions. Sometimes an overly powerful system cannot provide the desired climate either. A tractor is not suitable for pulling a garden cart, no matter how much power it has," Suurkask notes.

Perhaps most surprisingly, although heatwaves have become more common year by year, even large companies like Twitter are not ready for extreme weather. Twitter's former head of security revealed last August that it would not take much for Twitter to be "down" for weeks or months. It would be enough for the operation of a few data centers to be interrupted temporarily but simultaneously, Gizmodo reported.

A valuable lesson emerges from old experiences

There are solutions to this deepening IT headache, however. Grünberg recalls from his own experience a story that also hints at how to fight today's problems. "I remember a case from the more distant past where mobile network equipment in a data center overheated. Services were disrupted for thousands of people and the repair took days," says the current GDC CEO. At the time there were no proper data centers in Estonia, and the cause of the problem was a cooling unit failure. "Because the unit was not duplicated, cooling of the room stopped and the temperature of the equipment kept climbing. We learned of the problem when the equipment itself sent an alarm. There were no separate sensors in the room. Before we could react, the equipment switched off and the repair was complicated. In the end the lesson was that relying on a single cooling unit is not a reliable plan," says Grünberg.

Others have similar experiences to share. "From a previous job I recall a case where the server room air conditioner switched off as a result of a voltage fluctuation. There was no backup unit, so I soon received an alarm," says Aivar Karu, GDC's IT manager. "I was at home at the time, and since the workplace was nearby I got there fairly quickly. By then, though, most of the servers had already done a thermal shutdown. I remember one server's motherboard had warped so much from the heat that the memory DIMMs had fallen out," Karu shares.

Both examples reveal the core of the problem: reliance on a single unit. To answer the question in the title, the keyword here is the redundancy of supporting systems. It means having more of something than the minimum needed. While surplus things are often a nuisance, with business-critical infrastructure you cannot have too much of a good thing.

How are servers protected from heat in the Baltics' largest data center?

It pays to learn from the best. GDC's cooling systems are built on the logic that both the shared data hall and the private rooms all have backup units that engage when a unit that normally keeps the temperature in the right range stops working. Hazards have to be mitigated already at the design stage. "Our server rooms are designed and built on the logic that the power and cooling equipment has capacity headroom, and on top of that there are duplicate units in reserve. So we are ready for a higher load, and if something should happen, the backup systems take over," Grünberg points out the advantages of a building constructed specifically as a data center.

Location plays its part too. The GDC data center, for example, sits on a limestone bank on the edge of Tallinn, 43 metres above sea level. The cooling units themselves are a full 60 metres above sea level. That means the building is open to the sea winds, which bring constant relief, and on average the chillers have to be brought in for only about 300 hours a year.

The automation of GDC's cooling systems has been entrusted to artificial intelligence created by Siemens, a computer program capable of learning, which operates the equipment that keeps the temperature in the server rooms. It is an innovative solution in a global context and means significant energy savings.

Elsewhere in the world there are also plans that seem quite science-fiction. Microsoft, for example, has been experimenting for a decade with underwater data centers, where heat is no concern. Under the pilot project, the first prototype underwater data center, 2.5 metres in diameter, was placed in the Pacific Ocean at a depth of nine metres in 2015. There have also been ideas of building a nuclear-powered data center on the Moon, which would offer entirely new ways of addressing cooling.

But what to recommend to those who do not want to move to the Moon, underwater or even into the most reliable data center in the Baltics, but want to stay in their own server room or office building? How to ensure the necessary conditions there, so that you do not have to watch the weather forecast nervously all summer? Suurkask recommends the following:

• Map your needs as precisely as possible in terms of capacity, redundancy, temperature and humidity. Bear in mind that "just in case" wishes usually come not only with larger investments but also with running costs.

• Pay attention to the movement of air in the room: the ultimate goal is not to cool the rooms but the servers in them.

• Where possible (for sufficiently large systems), definitely consider so-called free cooling. Our climate offers opportunities to save energy.

• Although technically more complicated than free cooling, there are today several ways to reuse the heat from servers as well.

In short, there are several options. According to Grünberg, summer poses challenges for organisations operating in the digital field, but they can be overcome: "Just as it is worth putting on protective sunscreen before going to a hot beach, it makes sense to take preventive measures to ensure the reliability of your IT equipment and avoid heat-related outages."