The HGC is a field assembled, extruded aluminum ceiling suspension system designed to support diffusers, in-fill panels, and light fixtures in a variety of critical environments. The HGC is fully customizable to match the demanding and often crowded modern hospital and cleanroom ceiling layouts, while ensuring compliance with ASHRAE 170, FGI Guidelines for Design and Construction of Health Care Facilities, and USP 797/800. A continuous gasket prevents particulate migration between the ceiling plenum and the occupied space, while the sterile white powder coat finish is formulated to resist deterioration from hospital-grade cleaners and disinfectants.