What is the calculated airflow in CFM for a duct measuring 24" x 18" at a velocity of 728 FPM?

What is the calculated airflow in CFM for a duct measuring 24" x 18" at a velocity of 728 FPM?

• A. 1390 CFM
• B. 2184 CFM
• C. 1720 CFM
• D. 2560 CFM

Answer: (B)

To determine the calculated airflow in Cubic Feet per Minute (CFM) for a duct, you can use the formula: \[ \text{CFM} = \text{Area} \times \text{Velocity} \] First, you need to calculate the area of the duct in square feet. The duct's dimensions are given as 24 inches by 18 inches. To convert these measurements to feet, you divide by 12 (since there are 12 inches in a foot): - 24 inches = 2 feet - 18 inches = 1.5 feet Now, calculating the area: \[ \text{Area} = \text{Width} \times \text{Height} = 2 \text{ ft} \times 1.5 \text{ ft} = 3 \text{ square feet} \] Next, we can apply the velocity of 728 feet per minute (FPM) to this area. The equation to find the airflow (CFM) is: \[ \text{CFM} = 3 \text{ sq ft} \times 728 \text{ FPM} \] Calculating this gives: \[ \text{CFM} =

To determine the calculated airflow in Cubic Feet per Minute (CFM) for a duct, you can use the formula:

[ \text{CFM} = \text{Area} \times \text{Velocity} ]

First, you need to calculate the area of the duct in square feet. The duct's dimensions are given as 24 inches by 18 inches. To convert these measurements to feet, you divide by 12 (since there are 12 inches in a foot):

• 24 inches = 2 feet

• 18 inches = 1.5 feet

Now, calculating the area:

[ \text{Area} = \text{Width} \times \text{Height} = 2 \text{ ft} \times 1.5 \text{ ft} = 3 \text{ square feet} ]

Next, we can apply the velocity of 728 feet per minute (FPM) to this area. The equation to find the airflow (CFM) is:

[ \text{CFM} = 3 \text{ sq ft} \times 728 \text{ FPM} ]

Calculating this gives:

[ \text{CFM} =