What can you conclude about airflow in CFM if air velocity is measured at 400 FPM on a three-ton heat pump with a return grill of 3.4 square feet?

To calculate airflow in cubic feet per minute (CFM), you can use the formula:

Airflow (CFM) = Air Velocity (FPM) × Area (square feet).

Given that the air velocity is 400 feet per minute (FPM) and the return grill area is 3.4 square feet, the calculation would be:

Airflow (CFM) = 400 FPM × 3.4 square feet = 1360 CFM.

In the context of a three-ton heat pump, it's important to understand typical airflow requirements. A general rule of thumb is that a three-ton unit typically requires around 400 CFM per ton for effective operation. Thus, a three-ton heat pump would normally need:

3 tons × 400 CFM/ton = 1200 CFM.

Since the calculated airflow of 1360 CFM exceeds the typical requirement of 1200 CFM, this indicates that the airflow is higher than the normal range for a three-ton heat pump. Therefore, while the calculated airflow may not seem to fit the provided answer, the conclusion drawn in the provided answer reflects a misunderstanding of the relationship between CFM output and the heat pump's operational standards.

In this case, the