How is air volume typically controlled in a variable air volume system?

In a variable air volume (VAV) system, air volume is controlled by adjusting the amount of air delivered to a space based on the specific demand for heating or cooling in that area. This system is designed to optimize energy use and occupant comfort by providing the precise amount of conditioned air needed at any given time. The VAV system can respond to changes in occupancy or temperature requirements, ensuring that spaces receive just enough air to maintain the desired environment without overconditioning or wasting energy.

This dynamic adjustment is accomplished through the use of variable speed fans and dampers, which modulate the airflow according to the demand from the space's temperature sensors. This approach allows for greater efficiency compared to systems that rely on maintaining constant airflow or shutting off air completely, which do not effectively address varying occupancy and temperature needs throughout the day.