HVAC Contractor Practice Exam 2025 – The Complete All-in-One Guide to Exam Success!

Using manual dampers is the most commonly used method for adjusting airflow in a duct system because it allows for quick and straightforward control of the airflow in specific sections of the ductwork. Manual dampers can be adjusted to increase or decrease airflow as needed, helping to balance the system efficiency and ensure consistent temperatures throughout the spaces served by the HVAC system.

This method is practical and cost-effective, as it does not require significant alterations to the existing ductwork or additional equipment. It provides flexibility to the HVAC technician or building manager, allowing them to respond to changing conditions in the building, such as varying occupancy levels or equipment usage.

In contrast, changing the duct size is a more permanent solution and often involves extensive modifications that can be costly and time-consuming. Adding additional fans would also increase system complexity and energy usage, making it a less favored option for simple airflow adjustments. Installing air filters, while important for maintaining air quality, does not directly influence airflow distribution; rather, it addresses air cleanliness and system protection. Therefore, manual dampers stand out as the most efficient and practical method for quickly adjusting airflow within an existing duct system.