How do you determine the airflow in a ductwork system?

To determine the airflow in a ductwork system, the correct formula is the product of the cross-sectional area of the duct and the velocity of the air moving through it. This approach is rooted in the principle of continuity, which states that the amount of air flowing through a duct is the same across any cross-section, assuming there are no leaks or changes in density.

In practical terms, airflow is typically measured in cubic feet per minute (CFM). The cross-sectional area is calculated based on the shape and dimensions of the duct, while the velocity is the speed at which the air is traveling through that duct.

Using the formula involves measuring both the area (which will be in square feet) and the velocity (which will be in feet per minute). When multiplied, these values yield the total volumetric flow rate of the air, allowing HVAC technicians to assess whether the system is operating efficiently or if adjustments are needed.

This methodology is fundamental in HVAC design and analysis, ensuring that adequate airflow can be achieved for proper heating, ventilation, and air conditioning functionality.