Most data center operators would likely be pretty happy with a power usage effectiveness (PUE) rating of 1.07, considering the goal is 1.0 – meaning all your power is used for IT equipment. But if you can achieve a PUE of 1.07 when your data center is located in a hot desert city like Las Vegas – well, that’s nothing short of remarkable.
Yet that’s exactly what one Schneider Electric customer was able to achieve thanks to the implementation of an indirect evaporative cooling solution, says Joe Capes, Business Development Director for Schneider Electric’s Cooling Line of Business in the Americas, in a podcast for the Schneider Electric Data Center Blog. (OK, technically it was a 1.07 “partial PUE,” which is defined as the amount of power consumed by cooling infrastructure divided by the IT load.)
That should give you some indication of how far economizer technology has come. Economizers of all sorts take advantage of ambient conditions outside a data center – namely temperature and humidity levels – to more efficiently cool the inside, Capes says. The technology has really come to the fore since 2008, when ASHRAE changed its guidelines around recommended data center temperature, going from an upper end high of 77 degrees F to 80.6 degrees F, Capes says. The group also widened the band for how much moisture could be in the data center.
The changes opened up economizers as a viable solution in more locations and for more days of the year in existing locations, Capes says.
Take Las Vegas for example. “The unique thing about a place like Las Vegas is you do have very good dry bulb conditions – very low moisture content in the air,” Capes says. “While the temperatures do get fairly high during the day, it is cool at night, so even during those higher temperature degree days, you can run in indirect evaporative mode and at night take full advantage of an air-to-air exchange based on those lower temperatures.”
Indirect air using evaporative cooling is one of the top three types of economizer technologies, Capes says. It involves separating the inside and outside air streams, which means you don’t have to worry about particles from outside air contaminating anything inside the data center. That is a concern with two other types of economizer modes: thermal wheels, which Capes says are highly efficient, and direct fresh air with an evaporative assist.
To find out how much you may be able to save using economizer technology, check out the Cooling Economizer Mode PUE calculator, one of the many trade-off calculators you’ll find on the Schneider Electric site.
And to learn more about economizer mode and how it works, listen to our entire podcast with Joe Capes.