Using Outside Air to Cool Data Centers
A couple weeks ago we noted a rebate program at California utility PG&E that rewards companies who use virtualization to reduce the number of servers in their data center. It turns out PG&E also offers rebates to customers who use outside air to cool their data centers. This approach employs air economizers, which include a sensor and filter and allow outside air into the data center when certain levels of temperature and humidity are met.
Lawrence Berkeley National Laboratory is studying the use of air economizers at seven data centers that have participated in the PG&E program, hoping to address concerns that the use of outside air will introduce contaminants or excess humidity into the data center. SearchDataCenter summarizes the study and provides an overview of the issues with this cooling technique.
Using outside air to cool the data center is a strategy that is limited by geography, as facilities in warm climates won’t see any benefit. PG&E admits that it’s a tough sell for many data center managers, despite the potential savings. “You can get huge energy savings because you’re not using a chiller or compressor to provide cooling,” William Tschudi, a project manager at Lawrence Berkeley, said. “In a lot of climates, you can get quite a few hours of outside air cooling.”
That is what we do here in Seattle (I wonder if City Light has such a program?) and we see power usage drop up to 50% when the conditions are right, which around here, is quite often.