What component of the HVAC system spreads the airstream at the termination of the supply run?

The component that spreads the airstream at the termination of the supply run is the diffuser. Diffusers play a crucial role in ensuring that conditioned air is evenly distributed throughout a space. They work by altering the airflow direction and velocity, thereby promoting an even dispersion of air, which enhances overall comfort within the environment. Additionally, diffusers can include design features that help manage acoustics and aesthetics, making them a vital part of HVAC systems.

In contrast, louvres primarily serve as weather protection or to provide ventilation by allowing airflow through openings and are not designed specifically for spreading air. Backdraft dampers are used to prevent reverse airflow in duct systems, and turning vanes help direct airflow around bends in ductwork; neither of these components is meant for diffusing air into a space. Understanding these distinctions clarifies the important function that diffusers have in maintaining optimal air distribution in HVAC applications.