Rooftop ductwork is an essential form of heating, ventilation, and air conditioning (HVAC) system that is used in many commercial buildings. It consists of a network of pipes, ducts, and fans that are installed on the roofs of business structures to control temperatures inside and improve air quality. Using rooftop ductwork improves energy efficiency and saves money on energy costs. The term “rooftop ductwork” may also be used to refer to other types of HVAC equipment, such as smoke-control systems, fire protection systems, and even electrical systems. Understanding the official business definition of rooftop ductwork is important for businesses so they can make informed decisions about their HVAC systems.