Data center design: basic principles, pitfalls, and common mistakes

On July 15, 2025, the State Duma approved a law that establishes, for the first time at the federal level, a definition and rules for the operation of data centers. This regulatory act aims to systematize the rapidly developing sector and, at the same time, introduces significant changes affecting both large market players and small businesses.

Federal Law 244-FZ, dated 23 July 2025, “On Amendments to Articles 2 and 6 of the Federal Law “On Communications” and Certain Legislative Acts of the Russian Federation”

The first stage of design is concept development. In the case of a data center, it is not so much architectural as fundamental technical solutions that are important here: what is the planned capacity of the data center, what peak load should it be able to withstand, and what resources will be required for its stable operation. Unlike most other buildings and structures, a data center is primarily a complex of engineering systems, and the accuracy of the engineering solutions determines the success of the entire project.

The concept combines architecture, power supply, cooling, redundancy, and the operational model of the future facility. A master plan for the site is developed, and the architectural appearance of the building, its number of floors, room configuration, and placement of auxiliary systems are determined. In the case of a data center, engineering decisions are also made here that will support the operation of the data center: the redundancy scheme (4/3, 8/7, etc.), the necessary electrical and cooling capacity, the layout of the racks, and the load density. At the same time, CFD modeling is carried out to evaluate the efficiency of cooling systems in different modes. This is critical for data centers: errors in calculating thermal loads or underestimating local overheating lead to costly corrections in working documentation or even during operation.

Once the concept has been approved and the main engineering decisions have been agreed upon, the development of project documentation (stage P) and working documentation (stage RD) begins. At this stage, all decisions are detailed, drawings are produced for the general contractor, and specific equipment models are selected. New capital construction projects also require expert review; in the case of major repairs or reconstruction, stage P may not be necessary. But even in a simplified scenario, the data center must be designed so that power, cooling, architecture, security systems, and IT infrastructure work as a single entity.

The third stage is approval. The requirements for data centers differ little from the requirements that regulators impose on other building projects. However, there are two points worth noting.

• First, fire safety: data centers always require special technical conditions (STC) from the Ministry of Emergency Situations due to the large amount of infrastructure involved. The documents specify the building category, tolerances, evacuation routes, the location of fire-hazardous equipment, fuel storage facilities, etc., as well as firefighting and system layout diagrams.
• The second element is the sanitary protection zone (SPZ), which takes into account CO emissions, noise impact from chillers, and test runs of generators. Based on the results of the calculations, the SPZ undergoes an examination by Rospotrebnadzor and is registered in the cadastre. Incorrect calculations for noise and air can lead to delays at the examination stage.

Since data centers are primarily technical facilities, engineering systems play a key role—from diesel generators and UPS batteries to rooftop chillers and air conditioners in machine rooms. The designer must be familiar with their operational characteristics: how the equipment works under normal conditions, how it behaves under load, in heat or cold, during failures and in abnormal situations. Calculations for power supply and cooling are not limited to simply selecting “with a margin”; they involve developing scenarios. For example, the shutdown of one or two air conditioners, different diesel engine operating modes (continuous, prime, standby), and the dangers and advantages of different types of batteries are calculated. Engineers who are used to designing shopping centers or offices often underestimate the importance of such modeling, and this is precisely why critical errors can occur in data center projects.

In addition, the data center designer must calculate and take into account the noise level, emissions, and impact on surrounding buildings—and do so at the site assessment stage. For example, a facility located 200–300 meters from residential buildings must meet noise requirements in order to pass all approvals. In “normal” projects, where engineering systems play a supporting role, this problem can often be solved; for data centers, it is better to look for another site right away.

Thus, a data center designer is not only a specialist in developing 3D models, drawings, and documentation, but also an engineer who understands the technological logic of a data center’s operation and is able to calculate dozens of scenarios for its operation. They must understand the characteristics of the equipment, know its capabilities and limitations, features, and installation sequence, and develop design solutions that take all these factors into account. In mature teams, such as IXcellerate, this knowledge is based on experience: optimal solutions are well known to specialists and are incorporated into the project immediately, without a long search for compromises. This allows data centers to be built quickly, technologically correctly, and without financial losses.

CFD (Computational Fluid Dynamics) – this is computer modeling of air or fluid flows, allowing you to see their circulation in three-dimensional space—inside or outside an object. Data center designers must be proficient in using this tool, as it allows them to properly organize cooling—one of the most important factors in ensuring the smooth operation of a data center. CFD models show what will happen to air flows if one air conditioner or a group of air conditioners fails, how the temperature will change in narrow passages, and how wind roses will affect the operation of chillers and outdoor units.

CFD models take into account:

• the location of server racks and their heat dissipation;
• the configuration of air conditioners and the backup scheme;
• the air supply system—through raised floors or cold walls;
• actual temperature thresholds (normal, borderline, critical);
• failure modes: what will happen if one or more air conditioners fail;
• local overheating zones – “red zones” where the project does not work at all.

If, after turning on the virtual air conditioners, the model shows the room colored in green and blue tones, it means that the system is balanced. If yellow and red zones appear, it is necessary to change the layout, equipment, or airflow paths.

Airflow modeling is performed not only inside the designed premises, but also outside. For example, for refrigeration machines (chillers) to be installed on the roof, CFD allows you to calculate:

• How will the space under the units be ventilated?
• Will the thermal curtain create a risk of chillers losing their rating in the summer?
• Do decorative elements block the free flow of air?
• How will the chillers work during peak heat (especially in August)?
• whether exhaust gases from diesel generators will enter the air intake area.

For example, a bookcase covered with decorative panels may look beautiful, but it will actually block natural ventilation, increasing the air temperature around the chillers. A few extra degrees will cause the unit to reduce its cooling capacity, which will instantly affect the stability of the entire cooling system.

CFD also allows you to simulate the behavior of water-air cooling. Although there is currently little demand in Russia for 60+ kW racks that require water circuits, a modern data center must be able to quickly organize them. In particular, this option is available in IXcellerate data centers.

In general, when designing a data center, CFD modeling is not just an engineering tool, but also an early warning system. It allows you to conduct virtual operation of the future data center in dozens of modes, including emergency modes, before the first pile is driven into the ground at the construction site.

Design errors can occur at any stage of a construction project—in the concept, in the design phase, in the working documentation, on the construction site, or even during operation. However, in the case of data centers, these errors are often engineering-related: something was incorrectly calculated in the cooling or electrical systems. Such errors are difficult to notice during construction and expensive to correct in a finished facility, so it is important to identify them in a timely manner during the design phase.

Often, shortcomings occur at the concept stage. Incorrectly estimated thermal load or incorrectly selected air circulation routes lead to the selection of equipment that will not provide reliable operation in the specified modes or will fail under loads and during the warm season. Therefore, it is important to check the design on CFD models, identifying areas of overheating – “red spots.” An inexperienced designer may neglect this or check an insufficient number of operating scenarios in conditions of reserve capacity utilization.

The situation is similar with electrical systems: load calculation is not a summation of rated capacities, but a simulation of system behavior in various critical scenarios. Redundancy schemes (4/3, 6/5, etc.) define the logic of the branches; it is important to understand what load will fall on each of them in the event of one or more failures. An error in these calculations leads to overloads, losses, and, in the worst case, failures. Practice shows that building information modeling (BIM) technology helps to catch some of the collisions, but does not solve all problems. A three-dimensional model can show the intersection of communications and building structures, but it cannot replace an experienced engineer who sees and understands problems “live”: how to route a cable basket, how to combine a storm drain and a cable route, which places will create problems when installing large and heavy equipment. Often, visual and physical inspection, construction control, and the team’s experience save the project where automatic tools fall silent. External solutions also require attention: placing chillers on the roof or on racks requires calculations not only of the internal air balance but also of external flows. A rack covered with decorative panels, incorrect wind rose calculations, or the proximity of diesel generator exhaust to the air intake—all these architectural and engineering errors deprive the units of their rated power in hot weather and cause them to be derated.

The specifics of the equipment should not be forgotten: different types of generators have different operating modes, which affects their selection and calculation. UPS batteries—lithium-ion or lead-acid—have different requirements for fire safety, installation, and maintenance; the choice also determines the architecture of the premises, the installation time, and the monitoring system. Errors in accounting for operational characteristics result in rework, changes in passage dimensions, and route transfers already at the construction site.

Prevention of such errors requires careful concept development, CFD modeling with a maximum number of scenarios, careful verification of all engineering assumptions, and live construction control. This combination of engineering calculations and extensive practical experience allows IXcellerate specialists to avoid wasting time and money during data center construction.

Recommendations for data center designers: the key stage is thorough development of conceptual solutions. Errors such as incorrect engineering diagrams or underestimated thermal loads occur precisely at this stage. The concept should be based on real operating scenarios in the machine room, not just on the technical characteristics of the equipment.

CFD modeling must be carried out comprehensively, taking into account various operating modes and emergency situations: summer loads, partial shutdowns, and other failure scenarios. Errors in CFD lead to the wrong choice of cooling systems, number of air conditioners, air supply method, and redundancy schemes. It is unacceptable to limit oneself to calculating only the operating mode—the data center must remain operational during various failures, which forms the basis of design calculations.

Similarly, it is critical to calculate electrical loads taking into account power redistribution in the event of failures. Unforeseen scenarios can lead to critical overloads that manifest themselves after years of stable operation. Advance modeling of electrical system failures is a mandatory step. When placing external equipment (chillers on the roof or racks), it is important to assess airflow, thermal conditions in hot weather, and the impact of architectural elements (screens, panels, cornices) on temperature conditions and equipment reliability.

BIM technologies are effective for identifying conflicts at early stages, but they do not replace engineering experience and understanding of the specifics of a data center, where functionality is more important than aesthetics. Unlike office buildings, where compromises in the air conditioning system are acceptable for the sake of commercial space, such solutions are unacceptable in a data center.

The choice of equipment—UPS, batteries (lead or lithium), generators—must be based on the operational requirements of the data center. Equipment parameters (size, location, maintenance) significantly influence conceptual decisions.

Finally, it is critically important for the project team to constantly monitor construction. The engineering basis of a data center requires that the concept, project documentation, and construction be synchronized as much as possible. The project must be feasible “in concrete,” and on-site adjustments during construction must not disrupt carefully calculated engineering solutions.