Half of Medium/Large US Data Centers Use Economizers
The Green Grid released a survey of data centers' use of economizers, cooling technologies that take advantage of favorable outdoor conditions (air and/or water) to provide partial or full cooling without using a refrigeration cycle. Fifty percent reported that they were already using economizers, but it is not clear that economizer use translates into overall data center energy efficiency.
Survey participation was largely from US (90%) US and limited to facilities of 2,500 sq. ft. or more. Economizer use was highest (64%) in facilities of 50,000 sq. ft. or more.
Of those using economizers, 51% reported using them 2,000-5,999 hours per year. "Among those respondents whose data centers are not making full use of their economizers during available hours, their main reason is that their corporate standards for acceptable set points are more strict than the published standards." The report contains a wealth of other data about economizer use and non-use.
The survey appears not to have included other kinds of ICT facilities.
The most surprising (and discouraging result) was is regards to the leading indicator of ICT facility efficiency. "Over 70% of respondents reported their power usage effectiveness (PUETM) value, which was an average of 1.69. There was no statistically significant difference between the PUE reported by those who use economizers and by those who do not." This is unfortunately consistent with economizer/PUE data the EPA shared with us in June 2010.