Listening to music on the go or streaming TV shows from the couch, quickly ordering a new pair of pants, chat­ting with a friend over­seas — the digital world makes it all possible. And it all seems to happen invis­ibly and imma­te­ri­ally. However, nothing could be further from the truth: Every piece of infor­ma­tion relies on tangible infra­struc­ture, trav­eling as data packets made of elec­trons and photons through fiber-optic cables from A to B. The back­bone of our digital lives consists of densely packed undersea cables stretching for millions of kilo­me­ters, as well as count­less receiving and relay stations on land. If some­thing goes wrong there, it leads to delays, data loss, or — in the worst case — a network outage. 

Where the Internet has an address

Andre Hudson, Design Manager at Tyrone Fabri­ca­tion, knows this because it’s his job to make sure an outage never happens. Compa­nies that lay fiber-optic and telecom­mu­ni­ca­tions networks across the EU commis­sion Tyrone Fabri­ca­tion to build the asso­ci­ated crit­ical infra­struc­ture. Most of the time, these are very unas­suming, container-like build­ings. They house and protect the sensi­tive tech­nology that enables our daily use of the Internet. Take, for example, cable landing stations — the true hubs of the internet: This is where the optical signals from a subma­rine cable are trans­ferred to the terres­trial network. Or inline ampli­fiers, which boost the signal approx­i­mately every 70 kilo­me­ters along fiber optic routes. Or small fiber exchange cabins, like the one on the beau­tiful Irish island of Arran­more. The small cabin, which measures just a few square meters, houses complex tech­nology that bundles fiber-optic cables, trans­mits data traffic and moni­tors it — gener­ating a lot of heat in the process. 

“Heat is the biggest enemy of reli­able network oper­a­tion,” says Andre Hudson as he stands next to the little cabin on Arran­more with the wind whip­ping around his ears. “No matter what kind of crit­ical infra­struc­ture we’re talking about.” That’s why Ray O’Connor, Commer­cial Director at Akrivis, is also on site. The climate control specialist supplies modular cooling solu­tions for the stations that Tyrone is building. Hudson and O’Connor have been working together for many years; their compa­nies have been part­ners for more than two decades. In the begin­ning, Akrivis just supplied Tyrone with indi­vidual fans for smaller projects; today, they offer a broad port­folio for data center-related appli­ca­tions. And they rely entirely on fans from ebm-papst.

The heat load is the deciding factor

When Tyrone plans a new project, designing the cooling system is one of the first steps. The basis for this is the building’s loca­tion and the number of servers installed inside. For a typical inline ampli­fier, this usually amounts to around 24 19-inch racks. “The customer tells us how much heat each rack gener­ates during oper­a­tion. That can range from two to three kilo­watts, or even more with higher rack density,” explains Hudson. This deter­mines the esti­mated heat load, the place­ment of the equip­ment — for moni­toring, control, and power supply — and the cooling require­ments. Akrivis’s typical solu­tion for an inline ampli­fier consists of so-called dual cooling units, which Tyrone installs on the exte­rior of the building. “Dual” means that the units use ambient air for cooling in free cooling mode and only acti­vate a sepa­rate refrig­er­a­tion circuit when outdoor temper­a­tures are high. 

Using ambient air for cooling

To achieve this inter­play, Akrivis installs between three and six ebm-papst fans — specif­i­cally AxiEco and RadiCal — depending on the model. In free cooling mode, one centrifugal fan acts as a fresh air fan. It draws in cool, ambient air from the outside and exhausts warm air to the outside through AxiEco. RadiCal is intel­li­gently controlled based on the current IT load and ambient temper­a­ture, reaching an airflow of up to 3,500 cubic meters per hour.

If the ambient temper­a­ture exceeds the setpoint, the control system deac­ti­vates free cooling mode and switches on mechan­ical DX cooling. In this mode, another RadiCal handles air circu­la­tion through the refrig­er­a­tion circuit. AxiEco acts as a condenser fan, dissi­pating the heat to the outside and reaching an airflow of up to 6,000 cubic meters per hour. For the refrig­er­a­tion circuit, Akrivis uses a vari­able-speed compressor, which ensures precise temper­a­ture control. 

“Servers today have much higher temper­a­ture setpoints than in the past. At the same time, thanks to the vari­able speed of the fans, we achieve exactly the right temper­a­ture using less energy,” explains Ray O’Connor. “Even in hot regions like southern France, depending on setpoint, we meet in excess of 90 percent of the cooling demand using only ambient air.” This dras­ti­cally reduces the energy consump­tion and CO₂ emis­sions of crit­ical infra­struc­ture. According to Akrivis, this enables customers to achieve a power usage effec­tive­ness (PUE) as low as 1.04. This means that for every unit of elec­tricity consumed by IT systems such as servers, the infra­struc­ture requires only an addi­tional four percent for cooling. 

Secu­rity is the be-all and end-all

Regard­less of the building’s size, Tyrone always designs cooling systems with N+1 redun­dancy — that is, one unit on standby in case one fails. The fans them­selves are clas­si­fied as envi­ron­mental class H₂, which means they can with­stand direct contact with water over the long term without any risk of corro­sion. Both of these factors are impor­tant to customers for safety reasons. Network builders also prior­i­tize noise protec­tion. Espe­cially for build­ings located near cities, they conduct measure­ments before commis­sioning, explains Andre Hudson: “With Akrivis’s cooling solu­tion, we’re on the safe side. The fans are extremely quiet even at high speeds.” 

Akrivis’s modular, plug-and-play units make Hudson’s job easier. But there are also projects that unfold quite differ­ently. This year, a customer commis­sioned Tyrone to build a cable landing station, but since the customer already had a building near the sea, Tyrone was tasked with building inside it — a building within a building. “Space is becoming scarce in some areas, and our customer wanted to use the existing space. However, the ques­tion now was: How do we cool with outside air when there isn’t any?” The simplest solu­tion would have been to use units with a refrig­er­a­tion cycle. But for effi­ciency reasons, the customer wanted a solu­tion with free cooling.

Andre turned to Akrivis to work out how this could be done. The engi­neers modi­fied a classic CRAC unit so that it could deliver the required perfor­mance using fresh air supplied through air ducts. To ensure safety, they also devel­oped an emer­gency cooling mode: In the event of a three-phase power failure, the fans are powered by batteries, ensuring there still is cooling avail­able. Andre Hudson was satis­fied: “It’s precisely in projects like this that we see how well our collab­o­ra­tion works as long-standing part­ners. We rely on Akrivis’s exper­tise and know-how.”

Is AI changing every­thing?

Both exper­tise and know-how are becoming increas­ingly impor­tant skills because thanks to AI, every­thing is getting more intense and demanding. Data volumes are growing, and major cloud providers — so-called hyper­scalers — are pushing for more robust infra­struc­ture. Andre Hudson is already noticing this: “Our customers are having a hard time finding afford­able land. That’s why they’re already building capacity for the next 10 to 15 years — which means we’re installing more and more high-perfor­mance racks in small build­ings.” Ray O’Connor adds: “Today, we can cool up to 12 kilo­watts of heat output per rack with air. This increased heat load is rele­vant both for hyper­scalers and other AI-ready infra­struc­ture — and they are already talking about 100 kilo­watts and higher. These figures are changing the nature of our work and the cooling tech­nology required. Cooling  solu­tions are becoming even more impor­tant for guar­an­teeing constant avail­ability — from email to chat­bots and streaming services.” 

On Arran­more, there’s little sign of this yet. A small, unas­suming building on the edge of the coast quietly and reli­ably goes about its busi­ness. Out here, the cool breeze blows on its own.