A Sustainable Use For Excess Server Heat

The growth of remote, on-demand cloud computing services has been one of the main drivers of digitalization. For companies, it brings lower costs, improved security, and greater efficiency and flexibility. But the data centers the cloud relies on use a lot of energy and create a lot of heat.

Dresden-based company Cloud&Heat Technologies has found a novel and sustainable way to use this excess heat by diverting it into local and district heating solutions. Thanks to an innovative integrated direct-hot-water cooling system for its servers, 95% of the heat of its IT components can be used in this way.

Case study data centres and district heating sweden content

Cloud&Heat can provide servers in shipping containers, meaning they can be easily integrated with large-scale district heating systems. In Jordbro, south of the Swedish capital of Stockholm, two of these dry coolers, placed in 20-foot containers, can be seen close to a combined heat and power (CHP) plant run by Swedish renewable energy company Vattenfall. The plant uses biomass to generate energy, while heat is directed into a local district heating system. In what Vattenfall’s former head of strategy and business intelligence, Birger Ober, describes as “combined heat and compute,” the servers run on this clean energy, and the heat generated by them is also fed into the same district heating system.

Güntner V-shape VARIO Dry Coolers are installed on the roofs of Cloud&Heat’s containers. So where does Güntner fit into the equation?

“There are times when a district heating system grid can’t absorb all the waste heat,” says Anne Weisemann, thermal design engineer at Cloud&Heat. “So we use Güntner technology as back-up cooling or an emergency cooling system.”

Güntner has worked closely with the company for several years, providing not only its dry cooling technology but also its expertise.

“We first got in contact with Güntner in 2018, when we needed a dry cooler for our test infrastructure,” says Weisemann. “We were given advice about the possible accessories and the fan control options, and that cooler is still in use today. Güntner also offered valuable guidance when we were evaluating the use of different pipe and fin materials in corrosive atmospheres.”

“ON EVERY OCCASION WE”VE HAD GREAT SUPPORT FROM GÜNTNER. EVERY DRY COOLER WE”VE ORDERED WAS HIGH QUALITY AND ARRIVED IN PERFECT CONDITION. AND WHEN IT CAME TO TROUBLESHOOTING, THEIR TECHNICAL SUPPORT WAS EXTREMELY HELPFUL AND RELIABLE.”
ANNE WEISEMANN THERMAL DESIGN ENGINEER, CLOUD & HEAT

“Heat rejection didn’t fall within their field of expertise, so we supported Cloud&Heat on developing the engineering together,” says Jan Hübner, sales manager at Güntner. “Because the servers are often located outdoors, it was a critical issue to make sure the dry coolers were flexible enough for use in different weather conditions.

“THERE’S A NEED FOR MORE AND MORE DATA CENTERS, AND THERE’S ALSO A NEED TO DECARBONIZE DISTRICT HEATING, WHICH IN SOME PLACES STILL USES COAL. IT’S GREAT THAT WE CAN CONTRIBUTE TO BOTH THESE GOALS.”
JAN HÜBNER SALES MANAGER, GÜNTNER