We like to think that energy efficient servers and prudent management over our network infrastructures could help us save on electrical usage and cash. It turns out that the biggest slice of the data center power consumption pie is air conditioning.

Network World paints a not-so-pretty picture about what it's costing companies to keep those server farms chilled.

Numerous studies exist on power consumption in the data center. An Emerson Network Power study broke down data-center power usage this way: 50% for air conditioning, 26% for servers/storage, 11% for communications equipment, 10% for power-distribution equipment and 3% for lighting.

They recommend arranging data centers using the tried and true hot/cold aisle method. Failing that, dialing up the thermostat a bit also helps. After all, you shouldn't have to wear a parka to venture into those racks of servers. The folks over at Yahoo don't.