What Is a Diffuser? Diffusers are the vent covers through which climate-controlled air is delivered to a room. Floor, wall, and ceiling diffusers are common in both commercial and residential buildings. In a whole-home HVAC system, inevitably you are going to have rooms that get less use than others.

What does an HVAC air diffuser do?

What a Diffuser Does. When air blows directly out of your ductwork and through a register or grille, it is either being directly pushed out or down. Once installed, an HVAC diffuser will cause the air to spread out evenly in multiple directions, which allows for even distribution.

What is the difference between grilles and diffusers?

A special device used in supplying and extracting air vertically without any kind of deflection is called a grille. A device used to direct the air at different angles by profiled blades when the air is leaving the unit and going into the space is known as a diffuser.