What is the maximum recommended air velocity through a filter grill?

The maximum recommended air velocity through a filter grill is set to ensure that the filter operates efficiently while maintaining good air quality and system performance. An air velocity of 400 feet per minute (fpm) strikes a balance between effective filtration and the potential for noise and wear on the filter medium.

At lower velocities, filter effectiveness may be compromised due to inadequate air flow, while at higher velocities, the risk of filter damage and increased pressure drop occurs. A velocity of 400 fpm minimizes these risks, helping to extend the life of the filter and maintain system efficiency. This value is widely accepted in the HVAC industry and provides a guideline for optimal performance. By adhering to this recommended maximum, system designers can ensure reliable operation and effective air filtration.