As Data Centre adoption explodes in the Asia Pacific region, newer forms of cooling are emerging in the horizon, adoption of which is key to drive the sustainability agenda.

One of the key things to consider with Data Centre infrastructure is cooling. Addressing the W.Media’s Digital Week keynote, esteemed US Data Centre veteran Dale Sartor from Lawrence Berkeley National Laboratory spoke in detail on the new developments in Warm Water Cooling, which he believes can transform energy efficiency in Data Centres.

“There are many benefits. Using Warm Water Cooling can improve energy efficiencies, lowers Total Cost of Ownersip (TCO), improves reliability of systems, lowers operating costs and reduces capital costs,” he said.

Generally speaking, liquid cooling in Data Centres can be implemented with a broad range of technologies. These technologies range from transferring heat to a liquid which is far from the source. For example, Computer Room Air Handlers (CRAHs)) to immersion cooling where the heat transfer takes place on the surface of the hot electronic components, said Sartor.

In general, when the heat is transferred close to the source the cooling liquid supply can be warmer and still provide the needed cooling. The increased efficiency is driven by improved chiller performance and greatly improved opportunity for free cooling.

This assumes significance as many giants in the technology world such as Google and Microsoft, it is a ‘strategic asset’. Sartor also pointed out that this technology was there in the 50s at the beginning of Data Centre adoption but faded out. “People did not want water/liquid in their Data Centres,” he explained.

Most liquid-cooled solutions are hybrid technologies where only a part of the heat load is removed by the liquid. The remaining load is removed by traditional air cooling.

Thus, liquid cooling solutions that transfer heat near the source generally incur additional cost compared to air-cooled IT equipment in a standard rack. Also, these additional costs may substantially offset by the improved energy efficiency and potential capital savings of a final solution that includes liquid cooling near the heat source, pointed out Sartor.

Another logic in favour of Warm Water Cooling has to do with the fact that a chiller won’t be needed or in some cases can be significantly reduced. Also, lesser number of conversions with regard to AC/DC also helps. “As density of servers have increased this cooling technology will come in handy,” opined Sartor.

Like CRAH, InRow technology, which is a Schneider Electric (APC) trade mark is also finding takers. In this, hot air is pulled from the hot equipment aisle, cooled (chilled water), and returned into the cold equipment aisle. Another manufacturer provides an in-row type of unit that uses pumped refrigerant.

Either hot aisle or cold aisle containment will work with this technology. These in-row units are often controlled with variable speed fans and integrated controls.

Sartor also touched upon immersion cooling, in which the electronics are submerged in a non-conducting fluid. This technology can efficiently cool high-density electronics in Data Centres without the need for compressor-based cooling.

Since this system operates well using high temperature coolant, dry coolers can be used for heat rejection to the atmosphere, thereby eliminating evaporative water use almost anywhere in the world. “Liquid immersion cooling, especially with phase change ‘two-phase immersion cooling’, is a paradigm shift in the way electronics are cooled,” he said.