What is the typical range for allowable duct velocity?

The typical range for allowable duct velocity in HVAC systems is 800 to 1500 feet per minute (FPM). This range is generally considered optimal for balancing efficiency and noise levels. When duct velocities are within this range, the airflow is sufficient to transport conditioned air effectively throughout the system while minimizing turbulence and the associated noise that can occur at higher velocities.

Maintaining duct velocities within this range helps prevent issues such as excessive noise, which can be uncomfortable in residential applications, and ensures that the system operates efficiently without causing undue stress on the components.

Higher velocities, such as those in the second range of 1500 to 2000 FPM or higher, can lead to increased noise levels and the potential for ductwork and system damage over time due to vibration and turbulence. Thus, the selection of the 800 to 1500 FPM range reflects a compromise between performance, comfort, and system integrity, making it the most widely accepted standard in the industry for both residential and commercial applications.