Green Grid, one of several cross-industry bodies lobbying to advance energy efficiency in business computing, has just released free software that could provide data centre managers with clues on how much energy may be saved through the use of outside air.

For much of the year, the air outside of a data centre can be cooler than the air inside it. The new software will help determine how much free cooling a specific data centre can leverage.

“Finding cooling options that use less power is critical for those that want to save money,” said Vic Smith of The Green Grid. By inputting data on variables such as location, local energy costs, IT load, and facility load, a data centre or facilities manager could determine the specific potential energy savings for individual facilities.

The system is good for use in any of 33 countries and contains information from 608 weather stations throughout Europe.

Led by systems vendors such as IBM and Dell, Green Grid is also sponsored by businesses as diverse as the Nationwide US insurance company, Walt Disney and eBay. Its aim is to develop a top-to-bottom blueprint for energy-efficient data centres.

In addition to free cooling from outside air, the tool provides information about savings that could stem from the use of water-side economisers. These use water cooled by a wet cooling tower to cool buildings without operating a chiller unit.

When environmental conditions are optimal, the warm return water from the data centre is routed to the economiser. Once it returns to its desired temperature, the chilled water supply is then fed back to the data centre air handlers.

The operation depends on ambient conditions and the outside air must be sufficiently cool to allow for proper heat exchange.

The Green Grid has estimated that a 1 megawatt (1000kW) data centre in Luton, England, with power bought in at a cost of 13.6 cents per kW hour, could save as much as €340,000 per year using free cooling, or €210,000 per year using a water-side economiser.