Consulting-Specifying Engineer, Dec. 2016.
http://www.csemag.com/single-article/calculating-economics-of-hvac-systems/3d4582c584ab8a0192fda3f906d67a07.html

"Codes and standards, equipment efficiencies, energy modeling, commissioning, energy-conservation incentive programs, and lifecycle cost analysis all play into determining the economics of HVAC systems. Included are key aspects a mechanical engineer may need to consider when specifying HVAC systems into new or existing buildings, with a focus on the economic analysis provided to the client."