Currently in the LANline – Data center infrastructure and management


Water cooling is experiencing a renaissance

New concepts for the raised floor

If you take a look at modern companies, one thing quickly becomes clear: A well-functioning IT infrastructure is not only decisive for the competition. Driven by increasing digitalization, the need for high-performance data centers is also growing. But more efficiency also means more power consumption. To take account of environmental responsibility, companies need to take action to reduce power consumption while ensuring optimal cooling. Water should make a decisive contribution to this.

Particularly in the field of air-conditioning, data center operators are continually looking for solutions to save valuable energy. One approach: The minimization of air transport, with the return to the water-cooled CPU as the most consistent of all approaches. A somewhat less drastic concept is to minimize air transport in the data center by placing the water cooling system as close to the heat generator as possible. Several years ago, company Weiss Raised Floor Systems from Southern Germany, a region traditionally committed to innovation, and developed a water-cooled raised floor under the brand name HydroLogic Panel, with the aim to fully meet these high demands.

However, this should not be the end in the development of innovative systems around the water-cooled raised floor. By now, in addition to the HydroLogic Panel, the manufacturer now offers a complete product family on the market, consisting of the HydroLogic Panel, the XL and Micro versions, as well as the V and VDX versions. HydroLogic Panel XL and Micro each have a horizontally installed fan and heat exchanger, so working below dew point is not feasible. In the last two variations, however, two heat exchangers each V-shaped and four fans are installed. This makes it possible to work with very low water temperatures or – in the case of HydroLogic Panel VDX – with compressed refrigerants.

The panels are to combine the advantages of row and side coolers with a decisive advantage that is unique in data center climate control. You save valuable space. By this means, more server cabinets can be set up within the same rooms than when using conventional cooling solutions. Laying in front of and behind the racks thus leads to the already mentioned minimization of air transport. The product family includes options in sucking or pushing formats.

When focusing on increasing the cooling capacity, besides optimizing the air flow, the system also allows to lay the panels in the hot or cold aisle or to combine both types. Another approach is to integrate the system in addition to conventional chillers in the warm aisle to supplement their capacity and redundancy.

As a benchmark over other products, the smallest version of the HydroLogic series, rated at 10 kW, delivers a maximum power consumption of 140 watts. On the other hand, if required, cooling capacities of up to 50 kW per panel can be realized. With a standard size of 600 x 600 mm for HydroLogic Panel, XL and Micro as well as 1,200 x 600 mm for HydroLogic Panel V and VDX, the cooling tiles adapt to all conventional raised floors, allowing retrofitting in existing data centers. Prerequisite for installation is a minimum height of 450 mm. Looking more closely at the technical details, the point load values ​​are 3 to 5 kN. There is a certification according to DIN EN 12825.

“Flexibility is what sets us apart,” emphasizes Bernt Gottschling, Managing Director of Weiss Raised Floor Systems, when asked what distinguishes it from other concepts. So you could customize the height of the heat exchanger, the performance and / or the spatial conditions. The latest project of the raised floor manufacturer is a completely customized system for the High Performance Computing Center of the University of Copenhagen DTU. In a special container, a supercomputer consisting of 524 servers and 16,768 CPUs was integrated in 30 racks with a total heat load of 500 KW within 10 weeks after order.

“We got chosen because we were the only ones who could fully respond to the University’s requirements. For this purpose, we have re-dimensioned the devices as well as completely tailored the regulation device based on a PLC control from Phoenix Contact and integrated the entire control technology. The customer literally did not have the space to achieve the required performance in the existing space”, continues Gottschling.

Especially universities emerged as the main customers, alongside medium-sized companies. The trend toward edge computing also accommodates the water-cooled raised floor – as it can exploit all the benefits of water cooling with indirect free cooling and score as a cost and space efficient solution within smaller, decentralized data center units.

For the renowned data center builder and planner Prior1 from St. Augustin, Weiss supplies as an OEM-supplier the water-chilled raised floor for, among others, the product IT Smart Cage. It is a complete, pre-assembled data center that, due to its design, is intended to overcome the conventional barriers of data center construction and thus offers the operator the greatest possible performance on the available space. “We approached the development of the IT Smart Cage with a new approach. We wanted to accommodate as many units of height as possible in a compact and safe way in the smallest of spaces. For this, we have developed a completely new 19-inch concept”, says Curt Meining, responsible for the IT Smart Cage at Prior1. “By integrating the cooling in the raised floor, we simply get more space for servers,” adds Christoph Amann, the specialist in air-conditioning solutions at Prior1.