Building Operating Management, Jan. 2014, by Loren Snyder.
http://www.facilitiesnet.com/datacenters/article/How-HVAC-Economizers-Can-Help-Data-Centers-Meet-Energy-Codes-Energy-Star-Ratings-And-ASHRAE-Standards--14655?source=part

A 4-part article on energy use in data centers:
  1. Air-Flow Management, Economizer Use And Understanding PUE Can Help Improve Data Center Efficiency
  2. How HVAC Economizers Can Help Data Centers Meet Energy Codes, Energy Star Ratings And ASHRAE Standards
  3. Managing Data Center Air Flow With Hot Aisles, Cold Aisles Can Help Drive Energy Efficiency
  4. Tailor Data Center Energy Strategies To Business Needs