In what unit is airflow measured?

Airflow is measured in Cubic Feet per Minute (CFM) because this unit quantifies the volume of air that flows in one minute. It is essential in the context of HVAC systems, as it directly relates to how effectively a system can circulate air throughout a space. CFM is used to determine the capacity of heating, ventilation, and air conditioning systems to ensure adequate air changes per hour for maintaining comfort and air quality within residential and commercial buildings.

While Liters per Second is also a valid measurement for airflow, it is less common in the HVAC industry, particularly in the United States where CFM is the standard. Gallons per Hour pertains to liquid flow, which is not relevant in this context, and Inches of Water Column measures pressure, not airflow volume. Therefore, Cubic Feet per Minute is the standardized unit used for measuring and specifying airflow in HVAC applications.