MinersLoop, a Finnish company operating in IT and energy sectors, is expanding the AmbiHeat® heat pump system by Calefa with an additional 2 MW of cooling capacity. The system, located next to the company’s data center and commissioned in summer 2024, will be increased by 2.5 MW in heating output — doubling the site’s district heating production.
The modular AmbiHeat® heat pump system, built alongside MinersLoop’s data center in Seinäjoki, Finland, has been converting waste heat from cooling into district heating for just over a year. Now, the data center’s cooling capacity is being expanded with a second heat pump module.
“From the very beginning, we planned to scale up the heat pump system later on. Now was the right time for us to move forward with the expansion, and we were happy to do it with a trusted partner,” says Robert Schulman, Chairman of the Board at MinersLoop.
The expansion project, currently in the design and modular construction phase, will double the benefits delivered by the system. The new module, pre-assembled at Calefa’s factory in Ikaalinen, will be delivered to Seinäjoki this fall 2025 and installed next to the existing AmbiHeat unit.
“With this additional delivery, the total heating capacity of the AmbiHeat system will rise to 5 MW. The module includes reserved space for one more 2.5 MW heat pump, which will eventually bring the system’s total capacity to 7.5 MW,” says Antti Porkka from Calefa.
5 MW of Heating Capacity to the District Heating Network Already for the Upcoming Heating Season
The AmbiHeat heat pump system, located in a separate modular building next to the data center, provides cooling for the data center while recovering waste heat and converting it into district heating for Seinäjoki’s network.
The expansion consists of a single steel-framed module that includes one heat pump, a pumping group, electrical systems, and full automation. The module will be delivered to MinersLoop’s site and placed on pre-built foundations, completing the gabled roof structure of the existing heat pump facility.
Thanks to its modular design, the AmbiHeat system can be expanded quickly as cooling needs grow. This makes AmbiHeat an ideal solution for data centers, where computing power typically increases gradually over time.
Both the client and Calefa have retained the same project team as in the previous delivery a year ago, which is clearly reflected in the shortened timeline. The modular expansion of the AmbiHeat heat pump system will begin supplying heat to Seinäjoki’s district heating network already during the 2025 heating season.
“This is a great example of the results that come from well-developed collaboration and mutual trust,” Porkka adds.
Hydro system enhances data center cooling and waste heat recovery
MinersLoop’s data center in Seinäjoki currently utilizes two different cooling methods: water-based hydro cooling and immersion cooling based on oil baths. Waste heat from both systems is recovered and processed by the AmbiHeat heat pump system.
According to Schulman, the hydro system is even more efficient than immersion cooling in terms of both cooling and heat recovery, although it is still less commonly used.
“Hydro systems are a growing trend in data centers due to their efficiency. Their adoption has been somewhat slowed by the need for specialized technology,” Schulman explains.
The upcoming data center expansion will rely solely on water-based cooling, allowing the resulting waste heat to be more directly utilized by the heat pump system.
The already impressive performance of the AmbiHeat system, at times exceeding a COP of 5, is expected to improve further with the expansion.
“It will be exciting to see whether the system’s COP stabilizes above 5 in the future,” Schulman adds.
Waste Heat from the Data Center Is a Significant Addition to Local District Heating Production
MinersLoop sells the waste heat generated in its data center — refined through the AmbiHeat heat pump system — into Seinäjoki’s district heating network. According to Mikko Mursula from the local energy company Seinäjoen Energia, the data center is the most significant local source of waste heat for district heating.
“The annual energy we currently receive from MinersLoop accounts for about 3% of Seinäjoki’s total district heating demand. With the upcoming expansion, this share will rise to approximately 6%,” he explains.
Calefa’s modular AmbiHeat system serves as an excellent interface between the computing power market and local district heating production. Seinäjoen Energia has been positively surprised by the quality of the heat refined from the data center’s waste energy.
“This has been a pilot project for us in utilizing data center waste heat in Seinäjoki’s district heating network. It’s been great to see that the heat delivery is stable and reaches the desired temperature levels,” Mursula says.
The location of the data center at the end of a transmission line also supports Seinäjoki’s district heating network exceptionally well.
“From a technical standpoint, the placement of the waste heat source has been very successful, as it reduces the need for intermediate pumping in the network. Overall, the heat production from the data center is a very positive addition for us.”
Summary of MinersLoop’s AmbiHeat® Heat Pump System at the Data Center
- The AmbiHeat® heat pump system, delivered by Calefa, will soon provide MinersLoop’s data center with a total of 4 MW of cooling capacity.
- The waste heat generated during the cooling process is refined and fed into the local district heating network with a heating capacity of 5 MW.
- The system consists of two steel-framed modules, each housing a 2 MW heat pump.
- In addition to the heat pumps, the modules include pumping groups, electrical systems, and full automation for both cooling and heat recovery.
- Following the expansion, the overall efficiency of the heat pump system exceeds a COP value of 5.
- Thanks to its modular design, the AmbiHeat system supports the gradual growth of computing power in the data center, allowing for easy expansion with additional modules as needed.
