Demand in the United States for HVAC equipment is projected to increase 5.1 percent annually to $16.8 billion in 2015, according to a study that came out in November titled HVAC Equipment from The Freedonia Group Inc., a Cleveland-based industry market research firm. Advances will be stimulated by growth in residential and many types of nonresidential construction spending from a low 2010 base. Rising interest in more energy-efficient HVAC systems, in part spurred by regulatory changes, will also support increased demand — particularly in value terms given that more efficient systems and those using less environmentally harmful refrigerants are typically priced at a premium. Furthermore, public and private incentives will encourage owners to upgrade to models with efficiency ratings that are at or above Energy Star levels. These and other trends are presented in the 329-page survey.