What is the standard amount of air movement through the indoor coil of a heat pump?

The standard amount of air movement through the indoor coil of a heat pump is typically established at 400 cubic feet per minute (cfm) per ton of cooling capacity. This standard is critical because proper airflow is essential for the effective operation of the heat pump. At 400 cfm per ton, the system is designed to achieve optimal heat exchange, allowing the heat pump to efficiently transfer heat into or out of the conditioned space, depending on the mode of operation.

Airflow at this rate ensures the indoor coil effectively absorbs or releases heat, which helps maintain the desired temperature in the living area. If airflow is significantly lower than this standard, it may lead to inadequate heat transfer, reduced efficiency, or even system damage. Conversely, excessive airflow can create strong pressure drops, impacting the system's capacity to extract or reject heat.

In contrast, the other options either do not conform to the standard metrics for air movement in heat pumps or represent incorrect units of measure, making them less applicable in HVAC applications. Understanding this standard helps technicians ensure that heat pump systems operate efficiently and effectively.