BRACKNELL, U.K. — A new market study from BSRIA shows that data center traffic will grow at a 23 percent compound annual growth rate (CAGR), reaching 8.6 zettabytes by 2018. The move to off-site data centers is at the heart of this growing trend; however, it is not uncommon for data-critical organizations to retain enterprise data centers on their premises.

Cooling within the data center is a fundamental function of its smooth and efficient operation. However, cooling equipment is a major share of the cost within the capital expenditure outlay.

A combination of energy efficiency measures and rising energy costs have resulted in companies searching for ways of lowering their power usage effectiveness (PUE) and operating costs. This is especially crucial for the colocation data centers. In particular, big data companies have been criticized for their inefficiency, which is seeing their adoption of newer technologies.


BSRIA noted that the cooling segment of the data center market is undergoing some dramatic changes and has opened opportunities for a range of technologies.

Traditional close control cooling units — computer room air conditioner (CRAC) and computer room air handler (CRAH) units — are still fit for data center cooling in many countries. However, they are gradually losing share to newer technologies, especially evaporative cooling.

Evaporative cooling capitalizes on the feature of water as a natural coolant when warm and dry air is being humidified allowing for significant savings in operating costs. Evaporative cooling can either utilize pressurized or compressed water mist (evaporative system) or wetted pads media (adiabatic system).

It is also divided into direct (direct external air is allowed into the data center) and indirect (when external air does not mix with the internal air within the data center).

Lone Hansen, WMI manager - I.T. Cable Group, BSRIA, said, “One major downside with evaporative systems is that they consume water (which can itself be an issue if supplies are scarce) and the evaporative process can cause scaling of pipework and heat exchangers in high-pressure systems. The products are more suitable for new build projects due to the space and height requirements, as they are mostly large units. The use of water also raises the issue of Legionella, which needs to be given consideration in the design and operation of a facility.”

Close coupled solutions embrace a range of products, located close to the heat source: in-row, rack, rear door heat exchangers and overhead terminal units. These are more expensive and more suitable for higher density racks.

Liquid cooling (direct on-chip or immersion cooling) consists of taking the water or other source of heat rejection directly to the server. Depending on the application and the technology chosen the server equipment can be completely submersed into the coolant. However, there is still a certain stigma around liquids being at the heart of the IT equipment and it still remains a rather niche product, used only to deal with the extremely high density rack segment.

Both the UK and the U.S. are major data center users sharing a similar profile for the choice of cooling technology used. However, it is believed that as more applications move to off-site data centers, operators will increasingly be looking for locations in low-cost countries. This will drive the use of different technology used in these newer applications.

The U.S. accounts for approximately 40 percent of the worldwide precision cooling market. It is the market with the largest share of evaporative cooling, representing 26 percent of the total market.

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Publication date: 11/6/2015

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