How is the area in square feet of a duct calculated from its dimensions in inches?

To calculate the area of a duct in square feet from its dimensions in inches, the correct method involves converting the measurements from inches to feet before performing the multiplication. Since there are 144 square inches in a square foot (12 inches x 12 inches), dividing the product of the length and width in inches by 144 gives the area in square feet.

For instance, if the duct measures 12 inches by 24 inches, the area in square inches would be 12 x 24 = 288 square inches. To convert this measurement into square feet, you would divide by 144, which gives you 2 square feet (288 ÷ 144 = 2).

This conversion is fundamental in HVAC applications, where duct areas are commonly represented in square feet for airflow calculations, duct sizing, and system design. Understanding how to accurately convert and calculate these areas is crucial for effective HVAC system performance.