NEC is working on a new type of small data center unit that uses convection to slash power usage by a third, even in Japan's hot, sticky climate.

The Japanese electronics giant said Tuesday it has designed a new type of portable data center that can use the temperature difference between hot air exhaled from servers and untreated air from outside to create air flow and lessen the need for dedicated coolers.

While using convection to cool data centers is not a new concept, NEC said that most such facilities in Japan operate under old temperature and humidity standards published by ASHRAE, the American Society of Heating, Refrigerating and Air-Conditioning. The company said that newer standards, combined with its innovations in combining cooling and air flow, will allow for the greater power savings.

ASHRAE standards published in 2004 called for an operating environment of between 20 C and 25 C, and 40 to 50% humidity for enterprise servers and storage. But newer ranges published this year, expand that to between 15 C and 32 C, and 20 to 80% humidity.

NEC said that under the older ranges, only a tiny fraction of possible location and weather combinations in Japan can provide a suitable environment, meaning the vast majority of data centers are built totally enclosed. But under the new standards, NEC has calculated that it can use tightly controlled convection technology to allow for using outside air over 60% of the year in locations as diverse as urban Tokyo and chilly Sapporo in northern Japan.

The company said it has developed a portable data center module about six meters in length that can hold six racks of servers, with each running up to 8kW of power, which can use the new cooling method. Portable data centers are especially popular in Japan's cities, where the streets are narrow and land is expensive, as they can be squeezed in and installed at low cost.

The company said it aims to have a finalized version by 2013. It said it also hopes to apply the technology to larger, fixed data centers as well in the future.