Power Distribution Topology for Data Centers: Underfloor vs. Overhead Busbar Systems

Effective power distribution is a cornerstone of reliable data center operation. Two common topologies—Underfloor Distribution and Overhead Busbar Distribution—offer distinct advantages depending on your design priorities.

Underfloor Distribution

Underfloor distribution involves routing power cables beneath the raised floor of the data center. This method allows for efficient and organized distribution of power to IT equipment enclosures. Power cables are laid out in an orderly manner beneath the raised floor tiles, providing a clean and accessible pathway for electricity to reach the necessary equipment.

Advantages of Underfloor Distribution

✅ Maximizes usable space : By routing power cables underneath the raised floor, the overhead space in the data center remains clear for other infrastructure components.

✅ Flexibility : It provides flexibility in arranging and rearranging equipment within the data center, as power distribution is not restricted to specific overhead locations.

 Overhead Busbar Distribution

Overhead busbar distribution involves installing electrical busbars or power distribution units (PDUs) along the ceiling or overhead support structures of the data center. These busbars distribute power to IT equipment enclosures via cables or distribution branches.

Advantages of Overhead Busbar Distribution

✅ Easy accessibility : Overhead busbar distribution facilitates easy access for maintenance and installation since components are located above the equipment, eliminating the need to navigate beneath the raised floor.

✅ Reduced clutter : By routing power overhead, the floor space remains clear, reducing the risk of cable congestion and simplifying cable management.

✅ Scalability : Overhead busbar distribution systems can be easily expanded or modified to accommodate changes in power requirements or data center layout.

📛 Important Note

The main disadvantage of underfloor power distribution when compared with overhead busbar power distribution is the potential obstruction of airflow management. This placement of cables underfloor can impede the flow of cool air to IT equipment if not properly managed, leading to inefficiencies in cooling and potentially causing hot spots within the data center. Additionally, underfloor distribution may require more effort and complexity in cable management, as cables need to be carefully organized and routed to avoid interference with airflow and other underfloor infrastructure.

Both underfloor distribution and overhead busbar distribution are viable options for power distribution in data centers, and the choice between them depends on factors such as the layout of the data center, available space, cooling requirements, and scalability needs.