Transport Velocity is defined as

Transport Velocity is defined as

• A. The area of cross-section of duct
• B. The amount of airflow required inside a duct to keep a contaminant entrained throughout the system
• C. The static pressure downstream
• D. The velocity pressure of moving air

Answer: (B)

Transport velocity is the minimum air velocity inside a duct that is just enough to keep contaminants moving with the airflow rather than letting them settle out or deposit on the duct walls. This is all about ensuring that particles stay entrained and are carried through the system to be exhausted or filtered. That idea matches the described choice because it defines the airflow amount necessary to keep the contaminant entrained throughout the duct network. It’s a design criterion used to prevent deposition and to maintain effective contaminant removal. The other ideas aren’t about keeping particles in motion. The cross-sectional area of the duct relates to flow rate via Q = velocity times area, but it doesn’t specify a minimum velocity to prevent settling. Static pressure downstream concerns pressure losses and system resistance, not whether contaminants stay entrained. Velocity pressure describes the dynamic pressure of moving air, not the requirement to transport contaminants through the system.

Transport velocity is the minimum air velocity inside a duct that is just enough to keep contaminants moving with the airflow rather than letting them settle out or deposit on the duct walls. This is all about ensuring that particles stay entrained and are carried through the system to be exhausted or filtered.

That idea matches the described choice because it defines the airflow amount necessary to keep the contaminant entrained throughout the duct network. It’s a design criterion used to prevent deposition and to maintain effective contaminant removal.

The other ideas aren’t about keeping particles in motion. The cross-sectional area of the duct relates to flow rate via Q = velocity times area, but it doesn’t specify a minimum velocity to prevent settling. Static pressure downstream concerns pressure losses and system resistance, not whether contaminants stay entrained. Velocity pressure describes the dynamic pressure of moving air, not the requirement to transport contaminants through the system.