Finnish Limited Company MinersLoop refines the waste heat generated from cooling the data center into thermal energy using an AmbiHeat heat pump plant by Calefa. The refined energy is sold to the local energy company Seinäjoen Energia’s district heating network in Seinäjoki, Finland.
The MinersLoop data center in Seinäjoki, Finland, is the first of its kind globally, offering a comprehensive solution that combines the energy-intensive computing power market, innovative cooling technology, and the AmbiHeat heat pump plant developed by Calefa.
The AmbiHeat heat pump plant utilizes the data center’s waste heat with a COP value of 5, indicating very high efficiency. According to Robert Schulman, Chairman of the Board at MinersLoop, the efficiency of the heat pump system has at times even exceeded COP 5.
In this Article
- The heat pump plant scales with the growing computing power of the data center
- The data center's district heating production doubles
- Gradual utilization of the data center's waste heat
- Efficient recovery of the data center's waste heat
- Data center's waste heat to the district heating network
- Successful utilization of the data center's waste heat
- Summary of MinersLoop's data center cooling and waste heat recovery
The Heat Pump Plant Scales With the Growing Computing Power of the Data Center
The heat pump plant implemented by Calefa for MinersLoop’s data center cooling and waste heat refinement has been constructed in multiple phases. With the modular AmbiHeat implementation, the heat pump plant can be expanded in line with the growing computing power of the data center.
“It is typical for data centers that computing power increases gradually. Consequently, the need for cooling and the amount of waste heat also increases over time,” describes Antti Porkka from Calefa.
With the modular AmbiHeat heat pump plant, increasing cooling capacity can be achieved even on a tight schedule if necessary. The MinersLoop data center in Seinäjoki is a good example.
Download the AmbiHeat brochure and see how a modular heat pump plant is suitable for data center projects
The Data Center's District Heating Production Doubles
The first part of the heat pump plant built at the MinersLoop data center was completed in 2024. Two weeks after its delivery, the single-module heat pump plant produced 2 MW of cooling power for the data center. At the same time, it refined the data center’s waste heat into district heating with a thermal output of 2,5 MW.
In 2025, MinersLoop decided to expand the cooling capacity of the data center with a second AmbiHeat heat pump module.
“From the beginning, the idea was that the size of the heat pump plant would be increased later. Now was the right time for the expansion from our perspective, and we were happy to do it with a familiar partner,” says Robert Schulman, Chairman of the Board at MinersLoop, in 2025.”
Both MinersLoop and Calefa have the same project team for 2025 as they did for the previous year’s delivery, which is reflected in the project timeline. The expansion part of the modular AmbiHeat heat pump plant will supply heat to Seinäjoki’s district heating network by the heating season of autumn 2025.
“With this additional delivery, the total thermal output of the AmbiHeat heat pump plant will increase to 5 MW. The delivered module has been designed with space for an additional 2,5 MW heat pump, which will eventually raise the plant’s total capacity to 7,5 MW,” says Antti Porkka from Calefa.
Gradual Utilization of the Data Center's Waste Heat
2024 | 2025 | Future |
|---|---|---|
– 1 module – Cooling capacity: 2 MW – Thermal output: 2,5 MW | – 1 + 1 modules – Total cooling capacity: 4 MW – Total thermal output: 5 MW | – Possibility to expand the 2025 module with an additional 2,5 MW heat pump |
Efficient Recovery of Data Center Waste Heat Combines Immersion and Hydro Cooling
MinersLoop’s data center in Seinäjoki currently uses two different cooling methods; water-cycle hydrocooling and immersion cooling based on oil pools. The waste heat from both cooling systems is captured by the AmbiHeat heat pump plant and processed into the local district heating network.
According to Schulman, the hydro system is even more efficient than the immersion system in terms of cooling and waste heat recovery, although it is still less commonly used.
“In data centers, the hydro system is an emerging trend precisely because of its efficiency. Its popularity has been somewhat slowed by the special technology it requires,” Schulman explains.
The data center expansion will utilize only the water-cooled cooling solution. This allows the waste heat generated to be more directly utilized in the heat pump plant.
Data Center's Waste Heat to the Local District Heating Network
MinersLoop has an agreement with the local energy company Seinäjoen Energia for the supply of district heating. The waste heat generated from cooling the data center is refined directly into the local district heating network using the AmbiHeat heat pump plant.
According to Mikko Mursula of Seinäjoen Energia, the data center is the most significant local supplier of waste heat for district heating.
“The annual energy we currently receive from MinersLoop is equivalent to about 3 percent of the annual district heating demand in Seinäjoki. With the forthcoming expansion, this share will rise to about 6 percent,” he says.
The efficient utilization of the data center’s waste heat in the district heating network is also supported by the data center’s location: situated at the head of the network’s transmission line, the data center reduces the need for intermediate pumping in the network.
“Utilizing the waste heat from the data center will diversify our heat production profile, which will improve the reliability of heat supply.” Mikko Mursula Head of Heat Unit, Seinäjoen Energia Oy
Successful Utilization of the Data Center's Waste Heat
The European Union’s decision equires data centers to investigate the potential for recovering waste heat in the future. The legislation must be in place by October 2025 at the latest, and energy must be recovered where technically and economically feasible.
According to Antti Porkka, energy expert at Calefa, successful recovery of data center waste heat is based on both the location of the data center and on increasing the cooling capacity as the computing power gradually increases.
“It is important that the local energy company is involved in the discussion at an early stage to ensure that the data center’s waste heat is effectively utilized in the district heating network,” says Porkka.
In addition to location, the data center’s cooling system also plays a significant role in the utilization of waste heat. At its best, the data center functions as an element that balances the energy network, converting electricity during cheap hours into heat.
According to Robert Schulman from MinersLoop, the waste heat utilization data center project implemented in Seinäjoki is comparable to an electric boiler implementation in terms of both heat production and energy system balancing. At the same time, as a by-product of heat production, the data center project also enables the operation of a computing power market.
The implementation can even be compared to the increasingly popular electric boilers.
“If the same amount of electricity is directed to our data center as to an electric boiler, the same amount of heat can be recovered by cooling the data servers as would be obtained from an electric boiler,” Schulman summarizes.
3 Considerations for Utilizing Data Center Waste Heat
- The local energy company should be involved in discussions at an early stage of the project to ensure that the location of the data center is also efficient from a district heating network perspective.
- Different cooling systems for the data center offer different possibilities for heat recovery. The hydro system is currently considered one of the most efficient systems for heat recovery.
- The computing power of the data center is gradually increasing. A modular implementation for cooling, heat recovery and waste heat processing will serve the progressively increasing cooling demand.
Summary of MinersLoop's Data Center Cooling and Waste Heat Recovery
- The AmbiHeat heat pump plant supplied by Calefa provides a total cooling capacity of 4 MW for the MinersLoop data center.
- The waste heat from the cooling process will is refined into the local district heating network of Seinäjoen Energia with a thermal output of 5 MW.
- The AmbiHeat heat pump plant comprises a total of two steel-framed modules, each housing one heat pump with a cooling capacity of 2 MW.
- The 2025 module will have the possibility to be extended with one 2,5 MW heat pump, which will eventually increase the thermal output of the plant to 7,5 MW.
- In addition, heat pump plant modules include pumping groups, electrical equipment and automation for complete cooling and waste heat processing.
- The overall efficiency of the heat pump plant is above COP 5.
- The modularity of the AmbiHeat heat pump plant supports the progressively increasing computing power of the data center, allowing easy expansion of the heat pump plant with additional modules.
