Airflow

In engineering, the airflow or air flow is a measurement of the amount of air per unit of time that flows through a particular device.^[1][2]

The amount of air can be measured by its volume or by its mass. Typically it is measured by volume, but for some applications it is necessary to measure it by mass. Air is a gas, meaning its volume can vary with temperature.

Units

Typical units to express airflow are:^[3]

By volume

• l/s (litres per second)
• m³/h (cubic metres per hour)
• ft³/hr (cubic feet per hour)

By mass

• kg/s (kilograms per second)

Measurement

The instrument that measures airflow is called an airflow meter.

Control

The equipment that regulates the airflow is called a damper. The damper can be used to increase, decrease or completely stop the flow of air. A more complex device that can not only regulate the airflow but also has the ability to create an airflow is an air handler.

Uses

Measuring the airflow is necessary in many applications such as ventilation (to determine how much air is being replaced) and engines (to control the Air–fuel ratio).

See also

• Volumetric flow rate
• Air flow meter
• Damper (flow)
• Air handling unit
• Fluid dynamics

References