Which of the following describes the duct system in HVAC?

The duct system in HVAC is primarily responsible for transporting conditioned air throughout the building, which includes both heating and cooling air. A properly designed duct system ensures that air is efficiently distributed to various rooms, maintaining a consistent temperature and enhancing comfort. The effective movement of air is crucial for the overall performance of the HVAC system, allowing it to create and maintain the desired indoor climate.

In contrast to the other options, the duct system is not solely for heating (the first choice) as it is also utilized for cooling. It is typically not a completely sealed system; while sealing is important to improve efficiency and minimize leaks, some leakage is often expected (the second choice). Lastly, regular maintenance is necessary to keep the duct system clean and functioning optimally, which challenges the idea of it needing no upkeep after installation (the fourth choice).