Modular data centers are gaining popularity, but how are they made? ITdaily takes a look at the Dutch company Contour Advanced Systems in the Netherlands.
Anyone driving to the Contour Advanced Systems factory wouldn’t immediately expect to arrive at a place where a piece of European AI infrastructure is being built. We arrive in Arsseveld, a small village in the east of the Netherlands, far from the major traditional data center hubs in and around Amsterdam.
Playing with Lego
In this unexpected location, Contour and HPE are building modular data centers designed for the world of tomorrow. Upon arrival, the conversation quickly turns to Contour Advanced Systems’ USP: speed. “We are proud of the speed at which we build, deploy, and scale,” says Eric Klaassen, CEO of Contour Advanced Systems.
Inside, HPE first outlines the bigger picture. The traditional route—designing a data center, arranging permits, building, and testing—easily takes several years. For AI applications, that has become too slow. Computing density is rising to hundreds of kilowatts per rack, and existing data centers are often not equipped for this in any way.
This is where the modular approach comes in: units are assembled in the factory while the final site is being prepared, after which the various components are put together like building blocks once the site is ready. “Lego,” is how HPE’s Matthies Malte describes it. “All different blocks that together form a scalable whole.”
Theory first, then safety shoes
After the presentation, it’s time to put on safety shoes and head down the corridor into the factory. There, the story suddenly becomes visible. While workloads and time-to-market were discussed upstairs, several modular data centers stand in a row downstairs in various stages of completion. One unit has just arrived and is in the early stages of cabling; another is much further along in the process.
We don’t see mass production like in the automotive industry here, but rather a rhythm where repetition and specialization pay off. “We’re even running out of space; there are plans to build an entirely new hall.”
About forty to forty-five people work in production in this hall. One pod can be fully manufactured and tested in six to seven weeks. From project start to delivery, Contour usually estimates three to five months, depending on engineering and component lead times.
What is being built here looks like an ordinary container at first glance, but anyone who uses that word is immediately corrected. “These are absolutely not modified shipping containers,” says Geert Van de Paar, CTO at Contour Advanced Systems. “They are built from scratch with steel beam structures and insulated panels.”
The floor isn’t a standard floor either, as it’s extra reinforced to support the enormous weight of the racks. In ordinary data centers, stacking is fine, but here we’re talking about IT equipment that can weigh up to 3,000 kg per rack. That’s why Contour builds villages of containers, not stacking towers.
Water cooling is hip
In one of the units, the guide points up toward the roof. That’s where the heat exchangers are located, placed at a slight angle, with filters on one side and insulated cold water pipes on the other. “Each coil delivers 50 kilowatts, two per section, six in total. That accounts for 600 kilowatts of air cooling. The complete unit we’re standing in front of reaches 1.6 megawatts.”
For the latest AI systems, air cooling isn’t powerful enough. Water is “in” again at data centers, HPE emphasizes several times. Some systems are hybrid, operating on roughly one-third air and two-thirds direct liquid cooling. Others are entirely direct water-cooled.
Water is “in” again at data centers
Contour adapts the pods accordingly, right down to the piping configuration. The guide points to a modification he is clearly proud of. Pipes that previously ran vertically have been made horizontal, providing more space to better support different configurations.
The team behind the construction
Anyone who thinks the work begins the moment materials arrive can see how extensive the preparation is in the engineering room. There, a team of about 24 people works on the design. They start with an analysis of customer requirements and work with HPE to find the most suitable base configuration, such as a DC8 or DC16, and then personalize it. One customer might request a different rack layout, while another wants specific access security or fire suppression systems.
For a project for the French Ministry of Defense, they even had to account for 650 fiber optic cables, for which plastic cable ducts were more logical than metal ones. Everything is then developed in-house: from power distribution diagrams to production drawings, crane instructions, and layouts.
That engineering phase normally lasts between three and six weeks. After that, the factory depends on external parties and must wait for long lead times on crucial components. A busbar system can sometimes take up to fourteen weeks. The enclosures also come from subcontractors. Contour provides the drawings and expects different suppliers to build exactly the same thing.
“It works,” says Van de Paar: “Four units from three different manufacturers are standing here side by side, and to someone who doesn’t know any better, they are barely indistinguishable from one another.”
Smarter cooling
In the explanation of the climate system, it’s striking how differently cooling is viewed here compared to many traditional data centers. Instead of just pumping as much cold air as possible into a room, they follow the natural airflow. Warm air rises, is cooled at the top via heat exchangers, and then falls back down. The system measures temperature and pressure and controls the fans based on that.
There are multiple cooling zones and sensors. If the temperature rises, the system activates; if overpressure occurs, it scales back. “If you stand in such a pod long enough, you can literally hear the system reacting,” it is said.
Even fire detection is part of the thoughtful design here. A red plastic tube with small holes runs along the roof. It draws in air, analyzes all particles, and can sound an alarm even before a fire starts. Inside the units is a pull-out cabinet with fire extinguishers tailored to local regulations. It’s not surprising that this eye for detail makes Contour’s data centers popular in the defense world as well.
Fast infrastructure
The speed is particularly striking. Not just because these pods can be built faster than a traditional data center, but because they fit a market that must act increasingly quickly. HPE speaks of AI systems that are becoming denser, heavier, and more energy-intensive. Contour shows what that means in practice: steel reinforcements, piping, power switches, and engineering teams that work out how such a data center should function down to the valve level.
And so the image of that factory hall remains, where a few “boring” modules stand side by side. Still without GPUs, some even without doors or walls. But soon they will be compact data centers deployed worldwide as infrastructure for AI, science, or defense. Not containers, then, but infrastructure for the digital capacity that companies need to function optimally today.