What is the impact of restricted airflow in a PCA system on aircraft cabin temperature?

Restricted airflow in a Pre-Conditioned Air (PCA) system directly impairs its ability to maintain the desired temperature within the aircraft cabin. PCA systems are designed to deliver a specific volume of conditioned air (either cooled or heated) to the cabin to counteract heat gain or loss. When airflow is restricted, the volume of conditioned air reaching the cabin is reduced. This insufficient airflow means the system cannot effectively remove heat from the cabin in warm conditions or deliver enough heat to warm the cabin in cold conditions. The result is a cabin temperature that deviates from the set point, leading to passenger discomfort. Common causes of restricted airflow include clogged filters, blocked ductwork, or malfunctioning fans within the PCA system. Addressing these restrictions is essential to restore the system's ability to properly regulate cabin temperature.