Which of the following is essential for maintaining cooling performance in HVAC systems?

Regular replacement of air filters is crucial for maintaining cooling performance in HVAC systems. Filters play an essential role in the system's operation by trapping dust, dirt, and other particulates that can hinder airflow. When filters become clogged, airflow is restricted, leading to increased strain on the system and potential overheating. Furthermore, poor airflow can result in uneven cooling and can also diminish the system's efficiency, increasing energy consumption and costs.

In contrast, increasing the thermostat temperature can reduce cooling demands but does not address the underlying maintenance needs of the system. Minimizing ductwork is generally not a common practice since ductwork is necessary for distributing cool air effectively throughout the space, and improperly sized or configured duct systems can lead to inefficiencies. Lastly, using smaller refrigerant lines is not advantageous, as it can restrict the flow of refrigerant, leading to inefficient cooling performance and potential damage to the compressor. Overall, regular maintenance, including filter changes, is essential for optimizing HVAC system cooling performance.