What is the primary function of an air handler in HVAC systems?

An air handler plays a crucial role in HVAC systems primarily by circulating air throughout the system. This component is designed to move conditioned air—whether heated or cooled—throughout a building via ductwork, ensuring that indoor spaces receive a consistent and comfortable temperature.

In addition to circulating air, air handlers may include components like filters, fans, and coils that play secondary roles such as ensuring air quality by filtering out particulates or enhancing temperature control by using heating or cooling coils. However, their fundamental purpose remains centered around airflow management. This circulation is essential for maintaining even temperatures and improving indoor air quality, which are key objectives of any HVAC system.

The other options highlight functions that may exist in an HVAC system but do not define the primary role of an air handler. For instance, backup heating is typically provided by a separate unit or heating system, and while air handlers can distribute heated air, they do not themselves generate heat. Similarly, the cooling of refrigerant is a function that occurs in the condenser or evaporator coils, and generating electricity is outside the scope of any HVAC components.