What could be a consequence of undersized ductwork?

Undersized ductwork can lead to insufficient airflow and system strain, which is the correct consequence. When the ductwork is too small to handle the volume of air being pushed through by the HVAC system, it restricts airflow. This restriction can cause the system to work harder to maintain the desired temperature, leading to increased energy consumption and wear and tear on the HVAC components. Over time, this strain can result in reduced system efficiency, higher utility bills, and potential equipment failure due to overheating or overworking.

In contrast, other consequences such as overheating of the system might occur as a secondary effect of the strain but are not direct consequences of undersized ductwork alone. Reduced energy costs are not typically associated with undersized ductwork; rather, they are more likely to increase due to the inefficiencies created by the system working harder. Increased indoor humidity can also be a result of insufficient airflow but is better linked to lack of ventilation or other factors in the HVAC setup, rather than being a direct consequence of duct size alone.