Facebook said that it uses "100 percent outside air" to cool all of its own data centres, and that other data centre operators are typically over-cooling their facilities when they do not really need to do this.
By cutting air conditioning and making other changes as part of the Open Compute initiative, Facebook has seen an impressive 38 percent improvement in energy efficiency, the company claimed.
Frank Frankovsky, Facebook's vice president of hardware design and supply chain operations, said modern server hardware is much more robust than people imagine, and that Facebook has found it can operate quite happily without cooling even at temperatures as high as 35 degrees Celsius.
"Very few parts of the world are actually so hot that it would require you to run air conditioning" Frankovsky said.
He claimed that Facebook has been running its servers at this kind of temperature without seeing any adverse effect on the lifespan of the hardware.
In addition, most operators follow the ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) standards, which are very conservative and lead to "engineers in Texas having to wear sweaters to keep warm" because the inside air is chilled to such a degree, he added.
Even with air conditioning, data centre operators can do things to improve efficiency, Frankovsky advised. He said Facebook had eliminated uninterruptible power supply (UPS) units that lose energy through AC/DC conversion, and instead uses battery packs to do the same job.
"Existing data centres can also make themselves up to 30 percent more efficient just by doing things like separating the cold aisle from the hot aisle" He added.
The Open Compute Project, which Facebook started up about two years ago, brings together customers and technology vendors to develop new standards for efficiency in servers, storage and data centre architecture.
Facebook started the initiative because it could see that its ballooning storage and compute requirements would soon become prohibitively expensive, in terms of the energy needed to power the infrastructure alone, according to Frankovsky.
"We were on a massive growth trajectory and we knew we had to do things differently" he said.
By adopting measures from the Open Compute Project, Facebook has managed to reduce its power usage effectiveness (PUE) index down to a typical 1.07 compared with the industry average of 1.5. The latter figure means that 50 percent of the energy drawn from the grid is going to waste in many data centres.