Here's one way to use that excess heat from a datacentre - just send it to your local swimming pool.

A datacentre in Zurich is doing just that, when heat from a datacentre built in a bunker is being collected and transferred to the nearby pool as part of an innovative energy efficiency project undertaken by GIB-Services, a Swiss IT co-location company.

The bunker, capable of withstanding a nuclear bomb, was built in 1971 on the outskirts of Zurich to protect the Swiss Army communications team and has been out of use for several years. Accessible through a woodland path in the middle of a forest and built 7 meters underground, the shelter was purchased by GIB three years ago and turned into a datacentre in a project completed within the last few weeks.

Because the datacentre generates so much heat, GIB negotiated with local government officials to pump heat to an indoor facility with several swimming pools, according to IBM, which designed and built the datacentre for GIB.

The pool is being closed temporarily for repairs this summer, at which time the heat transfer system will be put in place, says GIB-Services CEO Hans-Rudolf Scharer.

"It isn't so complicated," Scharer says, explaining that water is used to transfer the heat. "We pump hot water to the swimming pool."

Excess heat generated by datacentre computers is collected in a storage area, where it heats up water that is piped to a heat exchanger at the pool facility. There, the heated water raises the temperature of the pool water. The process repeats itself as often as necessary with the heat exchanger, true to its name, exchanging heat from one part of the water to another.

The GIB datacentre will open to co-location customers in May and will have 300 to 500 customer servers across the facility's 200 square metres when at full capacity. The centre is expected to create 2,800 megawatts of heat each year, some of which will be reused by the pool heating programme.

IBM helped GIB build the datacentre as part of Project Big Green, IBM's $1-billion initiative to reduce energy used by Big Blue and its customers. IBM has recently announced several projects including the GIB one. IBM also built a green datacentre for Telecom Egypt and one for an Austrian furniture company called Kika/Leiner.

With more efficient building design and up-to-date server technology, energy costs can typically be reduced by 50 percent when a company builds a new datacentre or even retrofits an existing one, says Steve Sams, IBM's vice president of site and facilities services.

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