Hewlett-Packard thinks it has a cheaper way to cool data centers--pump the air conditioning only where it's hot. Its Dynamic Smart Cooling system, slated for sale by the middle of next year, will reduce energy use in a data center of 35,000-plus square feet by 20%, the company maintains.

The first part of the system is a grid of temperature sensors that covers a data center. Other vendors offer that. The second part, an HP server that can direct changes in the air conditioning units to level off the hot and cold spots, is what no one else is doing, says Illuminata analyst Jonathan Eunice.

HP also plans an unusual sales approach: Instead of a flat price, it will charge customers based on a yet-to-be-determined percentage of power cost savings. HP says power is about 40% of a data center's operational spending, and 60% to 70% of that is for cooling.

For HP, the cooling system marks an all-too-uncommon example of practical, homegrown innovation. "The folks at HP have long gotten a bad rap ... for having difficulty bringing HP lab innovations to market," says Eunice. "This is a pretty stellar exception."