Abstract: A combined ventilation and illumination system includes a ventilation assembly, a light fixture assembly, and a connector assembly. In an installed position, the system is installed above a ceiling of a room of building structure (e.g., a residence or workplace) to provide ventilation for the room. The system couples a light fixture to ventilation assembly below the ceiling. In the installed position, an air flow cavity is defined between the light fixture and the ceiling, where the cavity allows for air flow around the light fixture and into the ventilation assembly for eventual exhaust beyond the room in which the system is installed. The cavity includes a first critical distance that is sized according to operating parameters of a blower of the ventilation assembly to provide an adequate flow rate of intake air and to provide acceptable sound levels during operation of the system.