What is the purpose of an air filter in an HVAC system?

An air filter in an HVAC system serves the critical function of capturing dust, pollen, and other airborne particles from the air that circulates through the system. This is essential for maintaining indoor air quality and ensuring that the equipment operates efficiently. By trapping these particles, the filter prevents them from clogging the components of the HVAC system, such as the evaporator coils and blower fan. When the air is clean and free from excessive particles, it allows for better airflow and energy efficiency, which can extend the lifespan of the equipment and improve overall comfort in the conditioned space.

Other choices represent functions that do not align with the primary role of an air filter. For instance, increasing system pressure involves managing the refrigerant and airflow, which is unrelated to filtering air. Similarly, optimizing refrigerant levels deals with the efficiency and performance of the cooling system, while raising humidity levels is a function typically managed by humidifiers, not air filters.