MARILYN: the first high-density waterless datacenter

A datacenter designed by a professional for other professionals

Having observed the outdatedness and inadequacy of hosting offers currently on the market, Marilyn decided to create a computer center to meet the electricity and high-accessibility needs of IT professionals. The aim of Marilyn is to become a reference for businesses as much for its high accessibility as for the quality of services offered.

Marilyn, a new generation datacenter

  1. A robust and secure building
  2. 100% accessibility
  3. High density
  4. Environmentally friendly design and operation
  5. Invoicing per consumption
  6. No chilled-water systems
  7. No raised floor and drop ceiling
  8. Hot & Cold aisle containment


Marilyn: a patent, a brand for worldwide innovation

During design studies, the technical teams and partner consultancy company teams sought to obtain sound energy efficiency. Indeed, IT datacenters are extremely energy-intensive, as they require air-conditioning systems to cool their servers in operation. A study of a cooling method using ambient air was developed using a vertical construction and cooling system managed by recordings of external temperature. This is an innovative approach both on an architectural and technical level, and is the only one of its kind in the world.

The patent was granted by the INPI, the European Patent Office and the UPPTO internationally.


An innovative datacenter: reduced electricity consumption

The main innovation of the Marilyn concept is in the vertical construction of the building. The datacenter operates with total “free-cooling”, using external air to cool server rooms. The building has five floors and benefits from a natural stack effect and optimisation of aeraulic output. This is the first time in the world that this architecture has been used for a datacenter.

In contrast to other recent datacenters, Marilyn chose air-only cooling: there is no chilled water network. The site’s architecture enables high density: 10 kVA per server cabinet, i.e. 10 times more than current datacenters with air-only cooling.

These innovative technical choices enable a reduction of costs and greater reliability: in the event of cooling interruption, the site will not go above room temperature.

Over and above the energy savings, the vertical layout enables optimised organisation of the datacenter and reduced ground surface area requirements. This characteristic makes installation in urban areas possible. Consequently, the kVA unit cost per installed server cabinet in this type of installation is halved.


The total gain in electricity consumption is estimated to be nearly 35%, a saving of around 6 GWh per year compared to a traditional datacenter.
This saving represents the annual consumption of a classic office building of 150,000 m² surface area. The Marilyn energy output, or PUE (Power usage effectiveness), is 1.3, one of the lowest PUEs available on the market.