A refrigerant leak management system includes a return inlet assembly and a purge exhaust outlet assembly. The system also includes a sensor configured to detect refrigerant proximate an air handling enclosure of a HVAC unit. The system further includes a controller configured to control the system to drive air from a conditioned interior space of a building into an external environment via the purge exhaust outlet assembly when the sensor detects the refrigerant proximate the air handling enclosure by: actuating the return inlet assembly to close the return inlet assembly, actuating the purge exhaust outlet assembly to open the purge exhaust outlet assembly, and activating a reversible supply fan of the HVAC unit in a reverse direction.