Server Immersion Offers Cooling Benefits

Green Revolution Cooling (GRC) is claiming that its total immersion server system can reduce data centre cooling energy consumption by up to 95 percent.

The GRC CarnotJet System immerses the servers in a bath of non-conductive (di-electric) oil. The close contact between the mineral oil and the electronic components means that the fluid does not need to be much colder than the optimum operating temperature of the server to offer a much better cooling effect than air.

Numerous Efficiency Benefits

Air cooling requires a large temperature differential to provide substantial cooling – and that carries a high energy cost. In the first link of a water-cooled chain, a chiller has to reduce the water temperature to 7°C to cool a CPU near 75°C.

The GreenDEF fluid used by GRC is also more efficient because it only takes a small amount of power to move the high-heat capacity oil when compared to moving large quantities of air. GreenDEF is a colourless, odourless, non-toxic oil which, GRC says, has a low cost.

The fluid also offers other benefits by preventing dust gathering on the circuit boards and micro-arcing. This improves the efficiency of the circuitry and cancels any localised heating effects caused by the arcing.

The superior energy performance of the CarnotJet reduces costs in both average and peak power consumption. Even compared with Google’s green IT data centre figures, GRC’s system’s performance can reduce average data centre power by around 30 percent  and cuts peak power by much more, the company claims.

In the traditional data centre, a power outage in the cooling system has an immediate effect on the servers. Because the fluid holds 1,200 times more heat by volume than air, a similar power cut would take up to four hours before the servers showed significant deterioration.

The fluid even improves life for the hard drives because it has a cushioning effect that reduces vibration. The internal vibrations of the hard drives are usually added to by on-board cooling fans which, the company says, causes 50 percent of read/write failures. Fluid cooled circuits have no need for cooling fans so the vibrations are not a problem and the reduction in noise pollution is considerable.