Double-Decker Data Centre Container Is Cooled By Air

AST Modular has put a free-air cooling module on top of its data centre container. The resulting low-energy combination, which is in use at an efficient data centre in Iceland, is being sold by IBM.

The Natural FreeCooling system is an add-on to data centres built inside shipping containers, which are growing in popularity but have been seen as a less-efficient option than a purpose-built facility, said Marc Faig, AST Modular’s innovation officer, at a launch event in London.

Free-air cooling in a box

Free-air cooling uses outside air to cool servers, instead of running chillers which waste energy and reduce efficiency. However, the technique has been slow to arrive in containerised data centres, which were originally designed as mobile infrastructure for emergency use.

AST Modular, formerly AST Global, wassecond  in the containerised market in 2005, immediately behind Sun’s Black box containers, and is now providing the underlying technology for IBM’s containers.

The cooling container sits on top of the container which holds the IT equipment and uses a sealed circuit of cooling air, so outside air does not get directly into the IT kit. “Dust and pollution are the major cause of IT fires,” said Faig.

Fans circulate the cooling air, and can bring the “cold aisle” of the IT container down to within two or three degrees of the outside air temperature, and makes free-air cooling feasible in more of the world than people might realise, said Faig: “In Casablanca, you can use outside air cooling 60 percent of the time, thanks to the cold nights,” he said.

To extend the natural cooling, the system also includes evaporative cooling, but does not use a closed loop. “We’ve demonstrated this in an outside temperature of 35C,” he said – although at that temperature, the cold aisle went up to 27C, which is at the top end of most people’s recommendations.

Air cooling for a low PUE

The combined IT and cooling modules have a PUE (Power Usage Effectiveness) of around 1.05, in the same floorspace as a single container – admittedly twice as high.

The Natural FreeCooling system is in use at Thor, a facility in Iceland, which plans to be the greenest data centre in the world. Inside a large shed, Thor will use containers – and already hosts the Opera web browser’s servers in the first installed container.

Meanwhile, others are bringing outside air cooling to containers. This week SGI added an air-cooled module to its Ice Cube range of data centre containers.

Meanwhile, APC has launched EcoBreeze, which is a free-air cooling module in a shipping container, but is designed to be parked outside a building and used to cool a conventional data centre, eliminating the need for raised floors, and addressing a market created by the inclusion of free-air cooling in the ASHRAE standards, which inform US building laws.