i/O Data Centers, for example, "uses variable frequency chillers, pumps, cooling towers and air handlers to reduce energy consumption. By using only the power necessary to keep equipment running at optimal levels, i/o is able to operate energy-efficient data centers."

"You don't change the fan or the motor, you put a VSD on the motor. What used to be a single speed fan you can now slow down," notes EPRI's Symanski. "And by reducing the speed of a fan by 50%, with a variable-speed drive (VSD), you use only one-eighth of the power," However, Symanski cautions, "You have to make sure you don't get condensation and that the refrigerant doesn't freeze by slowing down too much."

There's even one easy component upgrade that can be done with some existing IT gear, Symanski points out: Replacing older power supplies with one of the new energy-efficient ones with certifications like 80PLUS and Energy Star.

"New power supplies may come in different versions -- Bronze, Silver, Gold and Platinum -- with correspondingly better efficiencies," Symanski notes. "Replacing an older power supply with a Platinum-level one can yield ten to fifteen percent energy savings, -- and the power supply is an inexpensive part."