What can imbalances in air flow through ducts cause?

Imbalances in air flow through ducts can significantly affect the pressurization and depressurization of rooms. When air flow is not evenly distributed, certain areas of a building may receive too much or too little air. This can lead to rooms becoming either pressurized, where air is pushed in more than it can escape, or depressurized, where more air is allowed to escape than is coming in.

These imbalances can result in various issues, including the potential for backdrafting of combustion appliances, which can introduce harmful gases into living spaces. Additionally, they can affect temperature regulation and comfort levels, contributing to uneven heating or cooling throughout the building.

In contrast, the other options suggest positive outcomes associated with balanced airflow, such as increased energy efficiency, enhanced indoor air quality, and noise reduction, which do not directly relate to the problems caused by airflow imbalances.