If a duct measures 24x18 inches and air flows at a velocity of 450 feet per minute, what is the volume of air moving through it?

To determine the volume of air moving through the duct, you first need to calculate the cross-sectional area of the duct and then multiply that area by the velocity of air flow.

The dimensions of the duct are 24 inches by 18 inches. To find the cross-sectional area, you multiply the length by the height:

[

\text{Area} = \text{Width} \times \text{Height} = 24 , \text{inches} \times 18 , \text{inches}

]

Calculating this gives:

[

\text{Area} = 432 , \text{square inches}

]

Next, to convert the area from square inches to square feet, knowing that 1 square foot = 144 square inches, you perform the following conversion:

[

\text{Area (square feet)} = \frac{432}{144} = 3 , \text{square feet}

]

Now that you have the area, the volume flow rate of air in cubic feet per minute (cfm) can be found by multiplying the area in square feet by the velocity of the air in feet per minute:

[

\text{Volume} =