In HVAC applications, a door frame serves to create a structured opening for access to ductwork for maintenance, inspection, and cleaning. This is critical because, in duct systems, having service openings allows technicians to reach various parts of the ductwork safely and efficiently. These openings can facilitate airflow adjustments and ensure that any blockages can be cleared without dismantling large sections of ductwork. Therefore, the door frame is integral in supporting these service openings, enhancing overall system maintenance and functionality.
In contrast, the other options do not accurately describe the primary role of a door frame. While support for electrical wiring, anchoring ductwork to walls, and preventing air leakage are vital functions in an HVAC system, they are not directly related to the specific purpose of a door frame, which is more focused on accessibility and maintenance rather than structural support or sealing.