Here's the latest status symbol to get your neighbours talking. NEC and Hitachi have teamed up to produce a new type of water-cooled PC.

The Valuestar W went on sale this week in Japan and packs a digital TV tuner along with a drive that can read and write Blu-ray Disc and read HD DVD. As it's intended to take the place of a TV so it has to be quiet, therefore NEC turned to water cooling to keep the noise low.

In most desktop PCs, a large heatsink is bolted to the top of the processor to dissipate heat, and a fan blows the heat outside of the case. A water cooling system pumps water through a heatsink on the chip to more efficiently get rid of heat. It's a more complex and costly arrangement, but a slower and quieter fan can be used.

NEC has already used water cooling in several PCs to reduce fan noise so the PC can't easily be heard. With the fan noise all but gone the company has now turned its attention to the next noisiest component: the hard-disk drive.

"It's difficult to make a hard-disk drive quieter so we decided to dampen the noise," said Hiroshi Sakai, manager of NEC Personal Products's common engineering department. NEC wrapped the drive in noise-dampening foam, but that means the device gets much hotter, so the processor water cooling system has been extended.

In the new PC water flows past both the processor and CPU to keep them cool.

The system was developed with Hitachi, which has built up years of water cooling knowledge through its mainframe systems business. Hitachi showed its first water-cooled PC prototype in 2002 and has worked with vendors including Hewlett-Packard on water-cooled systems.

The Valuestar W is the fourth generation of water-cooled PC from NEC and the heatsink has been substantially redesigned since the first PC went on sale in 2003. Back then it was nothing more than a copper pipe snaked over the heatsink plate, but the latest model, developed with Hitachi, pushes water through channels that are less than a tenth of a millimeter wide.

Hitachi licenses its water-cooling system to other vendors to help bring the price down. Hitachi itself has a small share of the PC market so it's unable to realise economies of scale through its own products, said Hideaki Gemma, general manager of Hitachi's IT thermal solution group. In addition to NEC the system has been licensed to some Taiwanese PC makers and some television makers, he said.

The fourth generation system adds about ¥10,000 (£42.77) to the cost of the Valuestar W, which is a lot in the competitive PC market place. But NEC hopes consumers will pay the extra money for reduced noise.