Ceiling diffusers are one of the few visible parts of an air conditioning system. Typically mounted in the ceiling of a home or commercial building, their purpose is to evenly distribute conditioned air throughout the room.
The term "diffuser" is actually interchangeable with "register" or "vent." However, when discussing home improvement, ceiling diffusers are more commonly thought of as the larger and more decorative alternatives to the standard rectangular vents that are typically found in a majority of production homes.
Diffusers are manufactured in a variety of shapes, sizes, colors and materials. The most prevalent style of diffuser used in contemporary home improvement are round with conical vent fins. These are considered to be aesthetically pleasing because the absence of square edges on the vent softens the overall appearance of a room.
Besides visual enhancement, diffusers are thought to improve the circulation and mixture of conditioned air with the existing air in a room. Diffusers are most often used during a remodel or HVAC system upgrade, because in order to receive the full benefit of improved air conditioning, it is necessary to replace or rebuild the supply plenum.