T-Bar Step Down Supply Diffusers go by many names, including cone diffusers, Lay-in diffusers, and T-Bar diffusers. The term “T-Bar” comes from the shapes of the railing that hold the ceiling tiles in a drop ceiling. The railing forms a grid of squares and T-Bar diffusers are designed to fit, or “lay-in” to those grid squares. The “cone” shape of the diffuser allows for maximum volume of airflow into the air-conditioned space.
