General formula to express flow rate of a ventilation system. The basic airflow concept in ventilation systems is called the “equation of continuity,” which expresses mass balance as air flows through different parts of the system. (Fundamentals of IH, 5th) Refer to other equations for specific configurations.
| Variable | Units | Description |
|---|---|---|
| V | Speed: Foot Per Minute | Air velocity |
| A | Area: Square Foot | Area of airflow (without any adjustments for flanges or other features) |