What could low operating pressures and low system amperage draw indicate in a residential split system?

Low operating pressures and low system amperage draw in a residential split system are indicative of low airflow across the evaporator. When there is insufficient airflow, the evaporator coil does not receive the necessary amount of air to facilitate effective heat exchange. This can lead to lower pressure readings because the refrigerant is not absorbing enough heat to vaporize fully, resulting in lower system performance.

Additionally, when the airflow is restricted, the system's compressor may operate with reduced load, thus drawing lower amperage as it works less to compress the refrigerant. This scenario can often be a result of dirty air filters, blocked ducts, or issues with the blower motor. Therefore, recognizing low operating pressures and low amperage draw as signs of inadequate airflow is crucial for diagnosing potential issues in the system and ensuring efficient operation.