Over the past year I’ve travelled all over the world, visiting data centre facilities and assessing their potential. It is no longer enough to set a standard from market to market. I’ve been looking at exactly what works from facility to facility, the preferred technologies, design specification and how to optimise underserved locations.

My travels have raised many questions to me about the way data centres are evolving and why. The facilities I visit sit at the core of millions of everyday transactions, so as the outside world changes, the inner workings of data centres need to do so to.

I’ve seen multiple different cooling techniques, innovative storage ideas and methods to improve power efficiencies. More recently, I’ve noticed the modern data centres are favouring newer, hard floor designs, which led me to ask, is the raised floor dead?

A raised floor in a data centre is an elevated floor that is built two inches to four feet above a concrete floor. It creates a space that can be used for cooling, electrical, and mechanical services. In data centres, raised floors are also used as a way of distributing cold air.

The raised floor worked very effectively to fit requirements of early data centre models. Some of the benefits included:

• Provided a cold air distribution system for cooling IT equipment
• Tracks conduits for data cabling
• A location for power cabling
• Copper ground grid for grounding equipment
• A location to run chilled water or other utility piping

Incompatible Features of the Modern Data Centre

Data centres have changed significantly and many traditional reasons for having raised floors no longer exist. Modern data centres with existing raised floors struggle to supply sufficient airflow to new high density IT loads that customer demand now requires. This is because of underfloor cable congestion and a low plenum height resulting in energy inefficiencies and hot spots.

The raised floor was once a standard feature in the traditional data centre, however a growing number of hard floors are now being implemented into modern builds. This is due to:

• Cost – raised floors are very expensive per square metre, as more cost effective and efficient alternative is rolled out, the raised floor is less desirable.
• Safety – tiles left open through user error can be a huge safety concern to operators and visitors especially on higher floors of up to four feet.
• Security – colocation facilities with partitions cages cite raised floors as a security concern as they create a new access point to cages.
• Increase in Capacity – modern data centres are built in a way which allows for future expansion but raised floors do not handle new heavy equipment well.

Hard Floor as an Alternative

The costs and concerns associated with a raised floor could be eliminated by a practical alternative. Designers are now gaining considerable experience in implementing hard floors into data centre designs.

Hard floors allow for overhead cooling with better airflow and multiple methods of cooling including rear door heat exchangers, row-based cooling with hot aisle containment, suspended ceiling return to computer room air conditioning with vented ceiling tiles and hot aisle containment with return to central cooling plant.

Due to the large amounts of experience within the design specification of raised floors it is likely to be around for a while. However, it is almost certainly going to become less common as efficient and cost-effective alternatives such as the hard floors are rolled out across modern data centres.