Late last year, a new Hewlett-Packard (HPQ) data center started up in Bangalore, India, that looks pretty much like any other data center. But if you've been inside one of these places, you'll notice a big difference: This one is warm. HP maintains a temperature of about 77F in the "cold" aisles, where the people are, and the aisles where heat is vented from machines are a toasty 86 degrees. It's the Miami Beach of data centers.
This is heresy. Most data centers are chilled down to about 60F in the cold aisles. But Chandrakant Patel, an HP fellow at the company's research lab in Palo Alto, Calif., who has specialized in computer cooling since the early 1990s, convinced his bosses three years ago that businesses needed to rethink data-center cooling. Rather than refrigerating an entire data center uniformly, he argued, they should selectively chill the areas that need it the most by monitoring hot spots and blowing cold air directly on them.
Here's how the system works: The Bangalore data center has a management system that controls all of its air conditioners, fans, and vents. Patel and four colleagues created an algorithm that takes in all of the data from 7,500 temperature sensors and software that instructs the air-conditioning system to provide just the right flow of air at the right place and at the right temperature.
Patel sees a data center and all of the machines in it as one large integrated machine rather than a lot of small independent ones. "Think of the data center as a giant computer," he says. "You have to approach the whole thing holistically, from the chips to the computers to the facilities." Most data centers were built before energy consumption became such a concern, and their operators didn't bother to coordinate all of their systems to achieve energy efficiency.
Patel tried out his ideas first in a small test facility in Palo Alto. But when he learned that an HP division in Bangalore was planning to build a 70,000-sq.-ft. data center, he pitched his system to the regional manager. "He was very passionate," says Subrahmanyam Vempati, a vice-president in HP's Systems Technology & Software Division. Vempati wasn't willing to commit until he visited the Palo Alto test site. Now his gamble is paying off. In the first year of operations, he expects to save 7,500 megawatt-hours of electricity, equal to the power consumption of 750 U.S. homes.
Late last year, HP began marketing a software product to data-center owners based on Patel's work, and now he's onto a new project. He's creating a system for measuring all of the environmental impacts of manufacturing and using a particular computer, so HP can create the greenest machines possible and customers can make more environmentally sensitive purchasing decisions. "We're helping figure out the energy costs of products from cradle to grave," Patel says.