Liquid-Cooled Data Center Raised Floor Selection Guide: 7 Key Engineering Considerations

As AI servers, high-performance computing systems, and high-density data centers continue to evolve, liquid cooling is becoming increasingly common in applications where conventional air cooling faces limitations.

While much of the attention in a liquid-cooled data center goes to servers, cooling distribution units (CDUs), and piping systems, the raised access floor should not be overlooked. It forms part of the physical infrastructure supporting equipment loads, cable management, underfloor services, and day-to-day maintenance.

A raised floor designed for a conventional air-cooled server room may not automatically be suitable for a high-density liquid-cooled environment. Higher equipment loads, concentrated loads, underfloor piping, and leak detection requirements can all affect the floor system design.

For this reason, raised floor selection should be based on the actual operating conditions of the data center rather than simply applying a standard air-cooled server room configuration.

7 Key Parameters to Check Before Selecting a Raised Floor

For a liquid-cooled data center that uses a raised access floor system, seven parameters should be confirmed during the early design stage.

These factors help determine the appropriate floor panel, pedestal and stringer configuration, floor height, reinforcement requirements, and layout.

1. Rack Power Density

Rack power density is primarily a cooling-system design parameter, but it also has an indirect impact on the raised floor system.

Liquid-cooled data centers do not all use the same cooling configuration. Some rely primarily on liquid cooling, while others combine liquid cooling with air cooling.

In a predominantly liquid-cooled environment, the raised floor may have less emphasis on underfloor air distribution and more emphasis on equipment loading, piping space, cable management, and maintenance access.

In hybrid liquid-and-air-cooled environments, the floor system may need to accommodate both equipment loads and airflow requirements, depending on the overall cooling design.

Before selecting a floor system, therefore, the project team should first confirm the rack power density and the cooling architecture being used.

2. Maximum Fully Loaded Rack Weight

High-density AI servers, GPU systems, and associated cooling equipment can place significantly higher loads on the floor than conventional server equipment.

The design should be based on the maximum fully loaded rack weight, rather than the empty rack weight.

It is also important to understand how the load is transferred through the rack feet or base structure and ultimately into the floor panels, stringers, and pedestals.

A floor panel that meets a specified uniform load does not necessarily provide sufficient performance under concentrated rack loads.

For heavy-duty areas, the floor system should therefore be selected based on the actual equipment load and the required concentrated load performance.

For projects with demanding load requirements, Huilian can provide high-strength calcium sulfate raised floor panels together with reinforced pedestal and stringer systems. The configuration can be adjusted according to rack weight, support layout, and project requirements.

3. Raised Floor Height

In a conventional data center, the space below the raised floor is commonly used for power and network cabling and, in some designs, underfloor air distribution.

In liquid-cooled facilities, this space may also need to accommodate cooling pipes, monitoring cables, and other services.

The required floor height therefore depends on the size and routing of these services as well as the available building space.

If the cavity is too shallow, pipes and cables may interfere with each other, making installation and future maintenance more difficult.

However, a higher floor is not automatically a better solution. Excessive floor height can increase project cost and may require additional consideration of pedestal stability and structural performance.

The appropriate raised floor height should be determined by coordinating the building structure, piping requirements, cable routing, equipment layout, and maintenance access.

4. Concentrated Load Capacity

Concentrated load is one of the key performance factors to evaluate when designing a raised floor for a liquid-cooled data center.

Traditional server rooms may place greater emphasis on uniform load requirements. In high-density liquid-cooled environments, however, equipment loads can be transferred through a limited number of support points.

Liquid-cooled racks and CDUs may therefore create relatively high localized loads.

A floor panel that meets its uniform load rating may still require additional consideration if the actual equipment produces high point loads.

The design should take into account rack foot positions, individual point loads, pedestal spacing, stringer configuration, and any required reinforcement.

For heavy equipment zones, the floor panel and supporting structure should be designed as a complete system rather than evaluated as an isolated panel.

5. Liquid Cooling Pipe Routing

The routing of liquid cooling pipes has a direct influence on raised floor design.

Depending on the data center architecture, cooling pipes may be installed below the raised floor or routed above the racks.

When pipes are installed below the floor, their routing should be coordinated with pedestal and stringer positions during the design stage.

The layout should provide sufficient space for installation, inspection, maintenance, and potential leak detection.

Pipe routing should also avoid unnecessary conflicts with floor supports. Otherwise, changes may be required during installation, increasing construction time and cost.

When most cooling pipes are routed above the racks, the underfloor space may be used primarily for power, network cabling, and other services. In this case, the raised floor design can focus more heavily on structural performance and cable management.

6. Leak Detection System

Liquid leakage is an important operational risk in liquid-cooled data centers.

Even a relatively small leak can potentially affect nearby electrical and IT equipment if it is not detected and addressed in time.

The raised floor system should therefore be coordinated with the data center’s leak detection strategy.

If the project includes leak detection sensors, the design team should determine their locations, cable routes, and installation requirements before the floor layout is finalized.

In areas where CDUs and cooling pipes are concentrated, visual inspection can also be useful for routine maintenance.

For these locations, Huilian can provide glass raised floor panels as a localized solution. Transparent panels allow maintenance personnel to visually inspect the space below the floor without repeatedly removing standard panels.

Glass panels do not replace an independent leak detection system, but they can complement the overall inspection and maintenance strategy.

7. Cooling Configuration: Liquid Cooling or Hybrid Cooling?

The final factor to confirm is the overall cooling configuration.

A predominantly liquid-cooled data center may place greater emphasis on equipment loading, piping space, maintenance access, and protection against potential leakage.

A hybrid liquid-and-air-cooled facility may require the raised floor system to address both equipment loading and airflow requirements.

This means there is no single raised floor configuration that is suitable for every liquid-cooled data center.

The floor system should be coordinated with the cooling architecture, equipment arrangement, piping layout, and operational requirements of the specific facility.

Why Should You Avoid Simply Reusing a Conventional Air-Cooled Data Center Floor Design?

A conventional raised access floor is generally designed around equipment support, cable management, and—in some facilities—underfloor air distribution.

High-density liquid-cooled data centers introduce additional considerations.

Rack and cooling equipment may create higher concentrated loads. Cooling pipes may occupy part of the underfloor cavity. Maintenance requirements can also become more demanding, particularly around CDUs and pipe connections.

Leak detection is another consideration that may need to be incorporated into the overall floor and infrastructure layout.

If a conventional floor configuration is applied without reviewing these conditions, problems may only become apparent during installation or operation. Examples include insufficient concentrated load capacity, conflicts between piping and floor supports, inadequate maintenance space, or difficulty accessing services below the floor.

The better approach is to coordinate the raised floor design with the rack layout, cooling system, MEP services, and piping design at an early stage.

Huilian Raised Floor Solutions for Liquid-Cooled Data Centers

Different areas of a liquid-cooled data center do not necessarily have the same structural and operational requirements.

Instead of using one floor type throughout the entire facility, Huilian can provide a combination of raised floor panels and support systems based on the requirements of each zone.

Heavy-Duty Areas in AI Data Centers

For areas containing high-density AI racks and liquid cooling equipment, high-strength calcium sulfate raised floor panels can be selected according to the project’s load requirements.

The panels can be combined with reinforced pedestals and stringers to provide a stronger supporting structure.

Additional reinforcement can also be considered around rack locations according to the actual rack footprint and load distribution.

For walkways and areas without heavy equipment, other raised floor configurations can be selected according to project requirements and budget, helping balance performance and overall project cost.

Hybrid Liquid-and-Air-Cooled Data Centers

Hybrid cooling facilities need to balance several requirements, including equipment loading, cooling pipe routing, and airflow organization.

High-load rack zones can use high-strength calcium sulfate panels with reinforced support systems, while other areas can be configured according to their specific loading and airflow requirements.

Where cooling pipes are routed beneath the floor, the support layout should be coordinated with the pipe routing before installation to minimize conflicts and simplify future maintenance.

CDU and High-Maintenance Areas

Areas around CDUs and concentrated cooling pipe networks may require more frequent inspection and maintenance.

Glass raised floor panels can be used selectively in these locations to provide direct visual access to the space below the floor.

This allows maintenance personnel to inspect pipe connections, equipment, and the surrounding area without repeatedly removing conventional floor panels.

Using different floor types in different functional zones can provide a more practical balance between performance, maintenance requirements, and project cost.

The Raised Floor Should Be Designed as a System

For a liquid-cooled data center, the raised floor is more than a single floor panel.

Its actual performance depends on the interaction between the panel, pedestal, stringer, reinforcement structure, and installation method.

For this reason, floor selection should not be based on a single load rating alone.

Rack weight, concentrated load, floor height, piping routes, equipment layout, cooling configuration, and maintenance requirements should all be considered together.

Huilian provides calcium sulfate, steel, and glass raised floor options and can combine them with reinforced pedestal and stringer systems according to the requirements of different areas within a data center.

This system-based approach allows the floor configuration to be adapted to heavy equipment zones, service areas, pipe-intensive zones, and general access areas instead of applying the same specification throughout the entire facility.

Conclusion

As high-density AI computing continues to drive the adoption of liquid cooling, data center infrastructure needs to evolve alongside the cooling system.

For liquid-cooled facilities using raised access floors, the selection process should begin with seven key considerations: rack power density, maximum fully loaded rack weight, raised floor height, concentrated load capacity, cooling pipe routing, leak detection requirements, and overall cooling configuration.

Among these factors, equipment loading and concentrated load requirements determine the structural configuration of the floor system, while floor height and pipe routing affect how the underfloor space can be used.

The most suitable raised floor solution is therefore not simply a matter of choosing one type of panel. It requires coordination between floor panels, support structures, equipment layouts, cooling systems, and maintenance requirements.

Huilian can provide project-based raised floor solutions for liquid-cooled and high-density data centers, including calcium sulfate, steel, and glass raised floor systems. By combining different floor types and support configurations according to actual site conditions, the system can be adapted to the structural and operational requirements of each area.

If you are planning a new liquid-cooled data center or upgrading an existing facility, project information such as rack power density, maximum rack weight, raised floor height, cooling configuration, and pipe routing can be used as the starting point for raised floor system selection.