(pronounced dih-FYU-zer)

Most likely you’ve heard this word related to a variety of meanings:

1. photographic diffuser – Some kind of screen (possibly of frosted glass or cloth) that for softens the image and/or the way light hits a subject. (Aging celebrities couldn’t live without these.)

2. aromatic diffuser – Usually a nebulizer that disperses essential oils into the air. (Aromatherapists and spa owners couldn’t live without these.)

3. hair diffuser – Either a built-in device or an attachment to a hair dryer that provides soft, dispersed heated air to preserve or promote natural curl in one’s hair. (Stylists couldn’t live without these.)

However, in the context of interior design, you will most often hear of a diffuser in one of two ways:

1. light diffuser – An apparatus (such as frosted and/or tinted glass or a type of reflector) that aids in evenly distributing the light produced by a lamp / light fixture.

2. air diffuser – A HVAC (heating / ventilation / air conditioning) device that regulates the path and velocity of air supplied by a mechanical system. People commonly refer to diffusers as vents, grilles or registers. Diffusers can come in several forms and designs (ex. slot, louver, lattice, radial) and materials (ex. stainless steel, aluminum, brass, bronze) and finishes (ex. decorative, paintable, outdoor).