Which of the following can be a sign of duct leakage in an HVAC system?

Inconsistent temperature throughout the building is indeed a key sign of duct leakage in an HVAC system. When ducts leak, conditioned air can escape into unconditioned spaces, such as attics, walls, or crawl spaces. This loss of air reduces the airflow reaching the intended areas, causing some rooms to receive too little heated or cooled air while others may be adequately conditioned. As a result, occupants often experience noticeable temperature differences from room to room, leading to discomfort and inefficiency in the system.

The other options, while they might relate to HVAC performance, do not directly indicate duct leakage. For instance, unusually low electricity bills could indicate a well-functioning system or reduced usage but do not necessarily correlate with duct performance. Increased humidity levels during summer can result from other issues, such as an undersized air conditioning unit or improper refrigerant levels, rather than leakage alone. Excessive noise from the outdoor unit typically indicates mechanics or operational issues within the compressor or fans, rather than suggesting air loss through ductwork. Recognizing the signs of duct leakage can help in addressing system inefficiencies and improving overall comfort in a building.