A duct delivering 300 CFM at a friction loss of 0.2" will have what velocity?

To find the velocity of air flowing through a duct, you can use the formula:

[ \text{Velocity (FPM)} = \frac{CFM}{A} ]

Where CFM stands for cubic feet per minute and A is the cross-sectional area of the duct in square feet.

In this case, we are given that the duct has a flow rate of 300 CFM. To determine the velocity, it is essential to know the size of the duct to calculate its area. However, for the sake of the multiple-choice context and provided pressure loss information, you can refer to standard air flow tables that correlate CFM, duct sizes, and corresponding velocities.

Given that the question presents a specific friction loss of 0.2", this typically aligns with a specific duct size leading to well-established velocities. In Heating, Ventilation, and Air Conditioning (HVAC) practices, it is common to have tables that help correlate the desired flow rate (CFM) to the resulting airflow velocities in feet per minute (FPM).

For a duct delivering 300 CFM at a friction loss of 0.2", the velocity that most closely corresponds to these measurements, as noted in established charts, is 900 feet