HPAC Engineering, Dec. 2016, by Ryan Geister.
http://hpac.com/air-conditioning/refrigerants-transition-impacts-hvac-system-design

"With the world’s attention increasingly focused on climate change, organizations are more attuned to carbon-footprint implications during the building-design process and the impacts buildings have on the environment. HVAC-system efficiency plays a crucial role in a building’s environmental impact. While it is important to choose equipment that delivers high-efficiency performance, it is even more critical to consider a building’s entire HVAC system during design."