In domestic heat pump applications, what is the minimum volume of supply air (cfm) per ton of cooling required?

In domestic heat pump applications, the minimum volume of supply air required is typically around 450 cubic feet per minute (cfm) per ton of cooling. This standard is based on the need to ensure adequate airflow for effective heat transfer and comfort in conditioned spaces.

When a cooling system operates, it absorbs heat from the indoor air and transfers it outdoors. To maintain efficiency and provide satisfactory indoor air temperatures, sufficient airflow is necessary to carry away the heat effectively. The standard of 450 cfm per ton ensures that the system can perform optimally without risk of overloading or underperforming, which could lead to uncomfortable indoor conditions or increased energy consumption.

While the other options suggest higher or lower airflow rates, they do not align with the established standards for residential heat pump performance, as lower airflow rates might result in decreased efficiency or insufficient cooling, and excessively high rates could lead to energy waste without corresponding benefits in comfort. Therefore, 450 cfm per ton is recognized as the minimum necessary airflow to maintain the balance between efficiency, effectiveness, and occupant comfort in heat pump systems.