Data centre design removes need for mechanical cooling and delivers 40 construction cost saving
Project facts
- LocationMäntsälä, southern Finland
- SolutionWe collaborated with Nebius to create an aeroplane-wing-shaped structure that uses outdoor air for adiabatic cooling, removing the need for chillers. The design achieved a PUE near 1.0, cut construction costs by 40%, and was developed as a modular blueprint adaptable to different climates and seismic zones.
- ChallengeThe goal was to design a high-tech data centre with very low energy consumption and reduced reliance on mechanical cooling. It also needed to minimise construction costs while remaining resilient in extreme climates.
Collaborative process helps deliver one of the lowest energy consumption data centres in the world
Nebius’ data centre in Mäntsälä, Finland, with four data halls and a total IT load of 40MW, stands as a leading example of energy-efficient engineering. The Haskoning Data Centre team supported every stage of the project, translating the business case into a design through a highly collaborative process that explored every possible way to simplify and optimise delivery. Alongside minimising energy use, this approach resulted in one of the lowest-cost high-tech data centres in the world.
A defining feature is the absence of mechanical cooling or chillers. Instead, outdoor air provides cooling through an adiabatic system¹, enabled by a combination of design choices, IT infrastructure, and operational adaptations. Working closely with Nebius’ IT department, their in-house development team optimised both the design and the operational strategy of the servers, which are also developed internally.
Harnessing external air for efficient cooling
“This use of direct air from outside for cooling is unusual,” explains Martien Arts, Mission Critical Facilities, Haskoning. “We designed a unique structure to enable it. The building is angled towards the prevailing wind direction, and the design, resembling an aeroplane wing, creates differential air pressures that draw the wind through the building. We designed and tested both the shape and its performance under varying conditions such as wind, pollution, rain, and snow.”
In addition, a heat exchange system links the data centre to the district heating network of a nearby village, providing local benefit. With a PUE just above 1.0, the building achieves exceptionally low energy consumption. By challenging design criteria and tailoring the facility to Nebius’ equipment and operations, we delivered a solution with construction costs reduced to nearly half those of typical data centre builds.
Next generation adaptable data centre design
Following the success of the Finnish project, we were commissioned to create a design adaptable across multiple climate and seismic zones. It needed the flexibility to operate in extreme heat or cold and to withstand seismic events or heavy snow.
Our modular blueprint addresses this through three key sections: the data centre, the cooling system, and the electrical infrastructure. Each element can be adjusted to local conditions, while automated design methods allow parameters to be modified quickly and efficiently.
¹ The physical phenomenon is used in which water that evaporates from the air, extracts heat, and thereby cools a surface.
