What might occur if ducts are not properly sealed?

Ducts that are not properly sealed can lead to significant issues with a building's heating, ventilation, and air conditioning (HVAC) system. When there are leaks in the ductwork, conditioned air can escape into unconditioned spaces, such as attics or walls. This means that the system has to work harder to maintain the desired temperature, leading to increased energy consumption.

As a result, the efficiency of the system is compromised. Rather than efficiently distributing the conditioned air throughout the living spaces, the system loses a portion of that air to the environment, causing it to run longer and consume more energy to achieve the same level of comfort. In addition to higher energy costs, improper sealing can also lead to uneven temperature distribution and increased wear and tear on the HVAC system, contributing further to operational inefficiencies and costs.

In contrast, the other choices do not align with the repercussions of unsealed ducts. Energy efficiency would decrease, not increase, and noise levels may rise due to airflow disruption, while indoor air quality could suffer due to unfiltered air entering the system and affecting the circulated air.