If a duct must measure 14" on one side to deliver 1400 CFM at a velocity of 1200 FPM, what should be the measurement of the other side?

To determine the measurement of the other side of the duct when one side measures 14" and it is required to deliver 1400 CFM at a velocity of 1200 FPM, it's essential to understand the relationship between velocity, flow rate, and duct dimensions. This relationship is expressed through the formula for calculating the cross-sectional area required for a specific airflow.

First, we can calculate the cross-sectional area needed to achieve the desired flow rate at the specified velocity using the formula:

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

Substituting in the given values:

[ A = \frac{1400 , \text{CFM}}{1200 , \text{FPM}} = 1.1667 , \text{square feet} ]

Next, since one side of the duct measures 14", convert this dimension to feet for consistency:

[ 14 , \text{inches} = \frac{14}{12} , \text{feet} = 1.1667 , \text{feet} ]

The area of a rectangular duct is calculated by multiplying its width