A slot diffuser is a building component used to deliver air to a room. These diffusers serve as a critical component in a heating, ventilation, and air conditioning (HVAC) system. This special shape makes it easy for builders to fit these diffusers into tight spaces, and helps to conceal the diffuser from view to create a more aesthetically pleasing design.

Contractors may utilize a number of slot diffuser installation methods. They are typically concealed within a suspended ceiling, but may also be placed in drywall partitions or ceilings. Some designs call for these diffusers to be installed in soffits above a window, or in a built-out area below a window sill. In some applications, the diffuser may even be placed in the floor. In rare cases, linear slot diffusers may also take the place of an exhaust grill to return air from a room back to the heater or air conditioner.