Google has recommended that data center operators allow their facilities to run at 80 degrees Fahrenheit saying most centers run at between 68 and 72 degrees with some running as low as 55 degrees.

It is estimated that for every degree rise in temperature four percent of energy costs are saved.
Datacenterknowledge.com reported that Erik Teetzal, an energy program manager at google said: "The guidance we give to data center operators is to raise the thermostat. Many data centers operate at 70 degrees or below. We'd recommend looking at going to 80 degrees.
The topic of data center operating temperatures was discussed in detail at the recent Datacenterdynamics conference in Amsterdam when pushing up the temperature of air side economizers from 20 degrees centigrade to 27 degrees centigrade in order to exploit the use of free air was explained in detail. The use of air side economizers, adjusting computer room air conditioning units and other methods of achieving optimum operating temperatures will be a key topic at the Datacenterdynamics London conference on November 11th and 12th.