What is the formula to calculate the CFM based on velocity and area?

The formula to calculate CFM (Cubic Feet per Minute) in relation to velocity and area is based on the relationship that defines volumetric flow rate. CFM represents the volume of air flowing through a system per minute.

The correct formula is derived from the basic principle that volumetric flow is equal to the cross-sectional area of the duct or pipe (in square feet) multiplied by the velocity of the air moving through that area (in feet per minute). Thus, when you multiply the velocity by the area, you obtain the total volume of air moving in one minute, which is expressed in CFM.

This relationship emphasizes how important both the area through which air flows and the speed at which it moves are in determining the flow rate. When either the area or the velocity changes, the CFM is directly affected. This calculation is crucial for system design and analysis, ensuring that HVAC systems operate efficiently and effectively.

Utilizing this formula allows technicians to evaluate and adjust airflow in various parts of an HVAC system, thereby optimizing performance and ensuring comfort in conditioned spaces.