What is the total area of a return register measuring 20 inches by 30 inches?

To determine the total area of the return register, you multiply its length by its width. In this scenario, the dimensions given are 20 inches and 30 inches.

The calculation would be as follows:

Area = Length × Width

Area = 20 inches × 30 inches

Area = 600 square inches

This calculation confirms that the total area of the return register is indeed 600 square inches, supporting the correctness of the chosen answer. Understanding this method of calculating area is fundamental in HVAC design, as it aids in selecting appropriately sized components for ventilation systems, ensuring efficient air flow and system performance.