As servers become increasingly energy-intensive, energy requirements are scaled up Data centers need solutions that provide continuous cooling - to avoid any potential undersizing of HVAC equipment likely to cause equipment failure - while ensuring that upgrades can be carried out without damaging the installation.

The solution is to use thermal High Density systems, such as cold aisle containment and air conditioning units, which ensure:

  • internal modularity of hot-swappable fans for ease of maintenance
  • no contact at all between the water supply connections (bottom of the unit) and the electrics (at the top)
  • simple and effective visual feedback to identify the alarms

These systems comply with 2 major thermodynamic principles: separating hot air and cold air, and optimizing the cold air circuit.


In addition to simply separating the hot/cold air flows by creating dedicated aisles, the cold aisle containment enables the aisles to be contained for optimized cooling. The hot air and cold air are separated when the room is designed, using roofs, panels and doors (at the entrance and exit). This very effectively reduces the energy consumption of the air conditioning units (visible reduction via the air conditioning unit consumption reports). The cold aisle containment provides an average of 30% energy savings.


For cooling right next to the servers.

Cooling the room 

This is done using CRAC (Computer Room Air Conditioning) units. Traditionally, cold air is sent into the raised access floor at a slightly higher pressure and exits via perforated tiles in the Cold Corridor. The hot air is evacuated into the hot corridor and reprocessed by the cooling unit.


These cooling solutions integrated in the aisle (in or between the cabinets) reduce the complexity of the installation and provide cooling as close as possible to the server. Particularly suitable for High Density solutions or rooms without raised access floors, row-based cooling solutions optimize the air flow so that it is as short as possible, which results in lower losses.

Exemple: the H2O system. Commonly called a chilled water cooling system, this uses water to exchange thermal energy between the secondary system and the primary outdoor system. When the system is located outdoors, a water/glycol mixture is used as a coolant to prevent freezing.The system can be designed as a single loop system, avoiding the need for an extra heat exchanger and therefore maximising the free cooling capacity. The water distribution infrastructure is commonly managed as a circuit for a whole room (or is part of a complete building).

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Smooth and constant cooling