What unit measurement is primarily used to express airflow in HVAC systems?

Airflow in HVAC systems is primarily expressed in cubic feet per minute (CFM). This measurement indicates the volume of air that is delivered or moved through an HVAC system over the period of one minute. Understanding airflow is crucial for ensuring the system operates efficiently, maintains comfort levels in various spaces, and meets the heating or cooling demands of a building.

CFM is utilized because it provides a clear and standardized way to quantify the performance of fans, ducts, and overall system efficiency. Proper airflow is essential for effective ventilation, indoor air quality, and temperature control. In HVAC design and analysis, accurately measuring and calculating CFM helps in balancing the distribution of air throughout a space, which is vital for the comfort and health of occupants.

Other measurements such as British thermal units (BTUs), gallons per hour, and watts pertain to different aspects of HVAC systems, such as energy transfer, fluid flow rates, and power consumption, respectively, but do not directly measure airflow. Thus, CFM remains the primary unit measurement when discussing airflow in the context of HVAC systems.