Energy consumption by heating, ventilation, and air conditioning (HVAC) systems
accounts for roughly 40 percent of total building energy consumption, and in
turn, buildings account for 35 percent to 40 percent of total worldwide energy
consumption. Thus, HVAC energy consumption in commercial buildings is a
key contributor to total global energy consumption. Driven by tightening
energy efficiency regulations and by demand for higher-efficiency buildings, the
technology for efficient HVAC systems is advancing.