How much outside air can be used to cool a data center? That depends where you are. But how much is there?

The Green Grid has launched a tool which uses information from 2,184 weather stations across the US and Canada and a database of observations from 1999 to 2008 based on Zip codes which will help operators determine how much free air cooling is available for data centers.

Using the tool the Green Grid determines that the total number of hours of available free cooling will always range from 0 to 8760 hours.

Using zip codes, the tool allows users in the United States and Canada to input their specific variables - such as local energy costs, IT load, and facility load - to determine the energy savings for individual facilities.

In addition to free cooling from outside air, the tool provides information about savings that could be obtained using water-side economizers.

For example:

A 1 megawatt (1000kW) data center in San Jose, zip code 95101,with power at a cost of 12.78 cents per kW hour, could save $66,000 per year using free cooling, or $160,000 per year using a water-side economizer.

A 1 megawatt (1000kW) data center in Herndon, VA, zip code 20170, with power at 8.14 cents per kW hour, could save $20,000 per year using free cooling, or $130,000 per year using a waterside economizer.

“Data centers with increasing IT loads require more power to cool them, so finding cooling options that use less power is critical not only for organizations that don’t have resources to build new facilities but also for those that want to save money,” said Mark Monroe, a director of The Green Grid. “For much of the year, the air outside data centers can be cooler than the air inside. The tool that The Green Grid has developed will help determine how much free cooling a specific data center can leverage.”

Members of The Green Grid will have access to a high-resolution graphical map of free cooling throughout the U.S. and Canada, while non-members can download a low-resolution version in the “Library and Tools” section of The Green Grid Web site. Maps by specific zip code can be obtained by contacting Weatherbank, Inc