IBM last month released its water-based cooling system, called Cool Blue, designed to lessen the heat produced by rack servers.

?There is a big drive for server consolidation these days. Companies are deploying dozens of servers in a data center half the size of those found a couple of years ago. At the same time, the processors in these servers are getting more powerful -- thus producing more heat,? says Bevan Lock, XSeries product manager at IBM SA.

?Air is a good coolant, but it is not as effective as water,? comments Lock. In fact, according to a report done by Knurr AG, a company specializing in thermal management for servers, in order to disperse 1 000 watts with a ten-degree temperature difference, only five litres of water is needed per hour, as opposed to 11,475 cubic feet of air.

A typical data center consists of hot and cold aisles -- cold aisles between facing racks and hot aisles at the rear of each row of racks. According to Lock, problems usually arise when a company decides to add another rack, thereby generating more heat.

?The company now has two options: it could either go for the costly, obtrusive route of upgrading its current air-conditioning system or it could install a Cool Blue rear door heat exchanger - provided of course that the new rack is manufactured by IBM,? he adds.

IBM?s Cool Blue solution comes in the form of a rear door heat exchanger, which clips on the back of any standard IBM enterprise 42U rack. ?The solution is easier to install and maintain than other cooling methods, and is capable of removing up to 50,000 British thermal units (BTUs) of heat -- up to 55 percent of the heat generated by a fully populated rack,? comments Lock.

?Companies will still need the traditional air-conditioning systems to create hot and cold aisles in the data center, but will not need to upgrade the air-conditioning system every time they decide to add more racks into the center,? he concludes.