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Data Center Cabling Above and Below – Raised vs Concrete Floors

Feature - Data Center Cabling Above and Below - Raised vs Concrete Floors - Cable Management Blog

It used to be that data centers were simply built with raised flooring. This was for several reasons: to allow for airflow, power and other cable routing, and flexibility during moves and changes. However, for most modern data centers, concrete floors, or slabs, have become a more common choice, with cables and even cooling running above rather than below.

But what is best for data centers, and is there still room for raised flooring in new and more modern data centers?

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Feature – Data Center Cabling Above and Below – Raised vs Concrete Floors – Cable Management Blog

The Reasons for Concrete Flooring

First, let’s look at why some data centers might choose concrete floors or a slab rather than a raised floor during construction, including power density, cooling, and more.

First, today’s high power density data centers need a lot of cooling, and a raised floor may not be up to the task. New fresh air systems and “hot aisle” containment systems do a better job than air routing under the floor.

Second, data centers are getting larger and denser at the same time. Components are actually getting larger, and cables are getting thicker. As the need for storage capacity rises, so does the demand on a particular data center. These larger data centers need more sophisticated cooling, not to mention the ability to hold more weight than a raised floor.

Contrariwise, even smaller data centers often lack the space to add ramps on raised floors, making their application impractical. In compact spaces, it’s difficult to achieve the proper power density with a raised floor.

These are all good arguments for concrete floors in data centers, but does that mean raised floors don’t really have a place? Not really.

Reasons Data Centers Might Want Raised Floors

Raised floors still have some uses in various spaces, including two primary scenarios.

  • Low Power Density might mean a lot of moves and changes, and especially in some caged hosting spaces, a raised floor is often still the best choice.
  • If water is needed to cool the IT space. In the case of some modern cooling systems, water is needed as part of the process, so raised floors provide a place to transport that water safety, without compromising electronic equipment.

However, these are just a couple of potential scenarios. Let’s look next at raised and concrete floors in a side by side comparison.

The Debate About Raised Floors vs. Concrete Floors

Here are some things to consider:

  • Irregular layouts – Once quite common, these led to the need for space under the floor for cooling and the need for flexibility for moves and changes. As equipment is modernized and standardized in both size and configuration, layouts are more predictable.
  • Cable length and brackets – Cables once had to be much shorter to protect against signal degradation. As fiber optics and high bandwidth Ethernet cables are used, it is no longer critical that cables be short, and the need for a lot of brackets to hold them and route them under the floor is no longer prevalent.
  • Power cables – Power cables once came from the bottom up, and it was necessary to have a raised floor for access. Now, racks and cabinets allow power connections from above, meaning the underfloor space is no longer needed. However, for older systems still in use, a raised floor is still a necessity.
  • Equipment grounding – Copper mesh used to be used to achieve a strong ground between devices. Newer cabling options mean this is no longer a concern. Their grounding wires ensure the integrity of each circuit.

In short, the more technology advances, the less raised floors are needed. But not every data center moves forward and updates at the same pace, and raised floors still remain useful in many cases.

Dust and Static Electricity

There is a final concern when it comes to concrete floors. While most modern devices have anti-static protection, there are some that are still vulnerable, even at low voltages such as a static discharge from a technician.

Solid floors are often constructed with grounded statics that may also use either anti-static panels or floor coatings to prevent the buildup in the first place. For raised floors, anti-static panels have been in use for a long time.

Of course, many will argue that the gaps between floor panels or even grout between panels applied to hard floors is a dust magnet, and dust is a killer in any data center. However, concrete floors can be coated with anti-static material that is seamless, allowing for easy cleanup and the prevention of dust buildup.

But what is right for your data center? Only you can look at all the options and determine what will work best with your overall cooling plan, moves, changes, and updates.

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About the Author

Louis Chompff - Founder, AnD Cable Products, Rack and Cable ManagementLouis Chompff, Founder & Managing Director, AnD Cable Products
Louis established AnD Cable Products – Intelligently Designed Cable Management in 1989. Prior to this he enjoyed a 20+ year career with a leading global telecommunications company in a variety of senior data management positions. Louis is an enthusiastic inventor who designed, patented and brought to market his innovative Zero U cable management racks and Unitag cabel labels, both of which have become industry-leading network cable management products. AnD Cable Products only offer products that are intelligently designed, increase efficiency, are durable and reliable, re-usable, easy to use or reduce equipment costs. He is the principal author of the Cable Management Blog, where you can find network cable management ideas, server rack cabling techniques and space saving tips, data center trends, latest innovations and more.
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