Energy efficiency in data centers: racks and aisles

The efficiency of a data center depends on many elements, from IT equipment to cooling. How air circulates between rack cabinets also matters: when cold and hot air mix, it becomes more difficult to maintain stable conditions in the room.

On 21 September 2026, the European Commission proposed a common classification system to make energy and water use in data centers more transparent. This development once again puts the focus on how these facilities are designed and operated.

What should be reviewed in the racks of a data center?

• The orientation of the cabinets. Their layout should favor separation between the cold air inlet and the hot air outlet.
• Doors and openings. Door ventilation and open spaces affect the air path.
• Cabling. An orderly installation facilitates maintenance and avoids unnecessary obstructions.
• Aisle containment. Depending on the data center design, it makes it possible to keep cold and hot airflows more effectively separated.

These measures do not by themselves guarantee a specific percentage of savings: the result also depends on the equipment load, cooling, and the configuration of each installation.

From an individual rack to the entire aisle

At Citadex we work with rack cabinets for servers, accessories, and cold-aisle and hot-aisle containment solutions. This makes it possible to assess both the needs of a specific cabinet and its integration into the data center as a whole.

If you are expanding a room, replacing racks, or reviewing their layout, it is advisable to start with the available dimensions, the expected load, the cabling, and the existing cooling system. With that information, it is possible to determine which configuration best fits the project.

Do you have a data center in the design or expansion phase? Explore our solutions for data centers and tell us what you need.

Source: European Commission — energy performance of data centres.