Data Center Floor Plans

Effective data center floor plans require the strategic placement of equipment in order to optimize air flow and cooling without adversely affecting work flow and the required service area, all while still providing for maximum availability and scalability.The floor plan design process involves significant evaluation and planning utilizing top down and elevation methodologies.

Planning and Pre-Design Phase

Detailed planning and pre-design is an important first step in creating an intelligent, efficient data center floor plan. By investing time and effort at this early stage, companies can save on capital and running costs, save time on correcting mistakes further down the design route, and save time on commissioning.

This process begins by determining a project budget for a particular layout for the IT and support infrastructure equipment including the computer room(s), mechanical room(s), electrical room(s), and any other supporting data center spaces that may be required. Next, if the project is for an existing data center, the conceptual design stage typically begins with a thorough on-site survey of the facility along with an examination of future growth constraints and the ability of the existing services to support the proposed floor plan.

Data Center Floor Plan Methodologies

The two primary methodologies for looking at a data center floor plan are the "top down" view and the "elevation" view.

Top Down View

To establish a data center floor plan using the top down view, designers begin by examining the work flow process and equipment location, accounting for equipment size and the necessary service space. This may involve analysis via Computational Fluid Dynamic (CFD) modeling, which can be performed for the under-floor air area as well as the area above the floor.

CFD modeling the airflow in a data center provides information to make informed decisions about where to place CRAC equipment, IT-equipment, perforated tiles, high density rack location units (RLUs), etc. Much of the software available today also allows mapping of both under-floor and overhead airflow obstructions to more accurately represent the environment. Furthermore, the CFD analysis will make obvious which cooling zones can be used for low density, medium density and high density equipment.

Once this assessment is complete, the floor plan design will implement a 'hot aisle/cold aisle' approach. This approach is the accepted layout standard for RLUs and should be adapted for both new and retrofit projects. In the 'hot aisle/cold aisle' approach, cold air is delivered via perforated tiles in the cold aisle. The heat builds up in the hot aisle and uses the ceiling height as a pathway back to the CRAC units. Additionally, row cooling can be accomplished utilizing a new CRAC type commonly referred to as an 'in-row' system.

In addition, the design team needs to address the specific power and cooling zones. Some zones of capability can be low-density RLU zones that require only raised floor row cooling, while others can be in-row cooling zones to provide medium-density cooling capacity. Still others can be cabinet cooling solutions for ultra high-density server environments. Provisioning cooling zones is most easily accomplished by matching the cooling techniques with the load requirements as a result of analyzing the CFD model.

Elevation View

The elevation view evaluates the design of the data center floor plan in three tiers: the layout below the raised floor, the layout above the raised floor, and the layout above the dropped ceiling.

To establish a data center floor plan using the elevation view, designers begin by segmenting the access floor. At this level, it is important to include a sub-floor with adequate drainage to draw water from spills or leaks away from sensitive equipment. Power cabling and piping for cooling systems should also run through the sub-floor. Data cabling may be installed at the top of the raised floor. The design should also incorporate free space in the middle of the raised floor to allow for unobstructed air flow.

Above the raised floor, the equipment in the room must be laid out to enhance performance and support high availability. This is typically done following the 'hot aisle/cold aisle' approach, allowing for work flow and equipment demands as discussed above. It's also important to note that the ceiling height in most rooms is typically a minimum of 9 feet, and the highest equipment placement should be no less than 18 inches below any sprinkler heads.

Next we come to the layout above the dropped ceiling. No plumbing or water pipes should pass over the room. Instead, it is common to pass these pipes at the perimeter to avoid potential equipment damage in the event of a water leak. An optional cooling approach presented by dropped ceilings is for the data center to utilize the ceiling plenum as a return air pathway depending on cooling requirements.

A broad spectrum of technical and strategic concerns must be taken into account when drafting a data center floor plan. The biggest factor to be considered when creating an effective data center floor plan is the power and cooling density to which the equipment is deployed. For best results, hire an expert consultant to ensure an efficient design that will lead to maximum availability and scalability.