What does duct leakage result in?

Duct leakage has a significant impact on the overall performance of an HVAC system. When ducts leak, conditioned air from the HVAC system escapes into unconditioned spaces, leading to a drop in the amount of heated or cooled air reaching its intended areas. This loss of air not only means that the system has to work harder to maintain desired temperature levels, ultimately causing it to operate less efficiently, but it also results in higher energy costs.

Additionally, when air leaks occur, they can introduce unfiltered outdoor air into the system, which could lead to air quality issues rather than improvements. Thus, the main consequence of duct leakage is the reduction of system efficiency and the associated increase in energy costs, making this the correct answer. It highlights the importance of sealing and maintaining ductwork to ensure optimal HVAC performance.