What is included in a duct system?

A duct system encompasses a range of components that work together to facilitate the movement of air within a building's HVAC (Heating, Ventilation, and Air Conditioning) system. The correct choice identifies that ducts, dampers, and fans are all integral parts of a complete duct system.

Ducts serve as the primary pathways for air distribution. Dampers are crucial to controlling airflow, allowing for regulation and balance within the system, which can enhance energy efficiency and comfort by managing the distribution of air to various spaces. Fans play an essential role in moving air through the ducts, helping to ensure that conditioned air reaches desired areas effectively.

This comprehensive view of a duct system aligns with the principles outlined in the International Mechanical Code (IMC), which emphasizes the importance of these components in ensuring proper ventilation and air movement. The combination of these elements is vital for the system's overall performance and efficiency in maintaining indoor air quality and temperature control.

In comparison, other options are limited in their scope. The inclusion of only ducts, or ducts and fittings, neglects critical components like dampers and fans, which are necessary for effective airflow management and system operation. Therefore, the highlighted option correctly encompasses the essential parts that make up a fully functional duct system.