Consulting-Specifying Engineer, May 2014, by Peter D. Zak.
http://www.csemag.com/single-article/energy-management-and-water-heating-systems/ead2ce605965e4cf773a4842cb5ee1b0.html

"Over the years, HVAC engineers have been challenged to provide more efficient and sustainable designs that meet societal demands to reduce the overall carbon footprint of a facility. Performance guidelines provided by programs such as the U.S. Green Building Council, Green Globes, and Energy Star provide guidelines for energy efficiency, while agencies such as the Environmental Protection Agency (EPA) and the Dept. of Energy (DOE) establish compliance guidelines for commercial HVAC systems."