Ducts that terminate in a manhole should have what component at their end?

The inclusion of both end bells and duct terminators at the ends of ducts that terminate in a manhole is essential for several reasons. End bells are used to guide the flow of air or to direct it smoothly into the duct system, helping to reduce turbulence and potential for damage to the ductwork. They also help in preventing debris from entering the duct, thus maintaining the integrity of the air or materials being transferred.

Duct terminators serve a complementary purpose by providing a finished or sealed end to the duct, preventing moisture and environmental factors from entering. Additionally, duct terminators can include features designed specifically to assist in drainage or ventilation, thereby enhancing the overall functionality of the duct system.

By requiring both components, the design ensures that not only is the airflow optimized, but also the duct system is properly protected, ultimately increasing its efficiency and lifespan. This comprehensive approach is crucial when dealing with ducts that lead into manholes, which are often exposed to various environmental challenges.