Floor Diffuser
(6)
Sidewall Register
(16)
Ceiling Diffuser
(20)
Grille
(8)
T-Bar Diffuser
(12)
Accessories
(7)
Clamp
(23)
Door Vent
(2)
Ceiling Diffuser are very common in heating, ventilating, and air-conditioning systems. Diffusers are used on both all-air and air-water HVAC systems, as part of room air distribution subsystems, and serve several purposes:
When possible, dampers, extractors, and other flow control devices should not be placed near diffusers' inlets (necks); either not being used at all or being placed far upstream. They have been shown to dramatically increase noise production. For as-cataloged diffuser performance, a straight section of duct needs serve a diffuser. An elbow, or kinked flex duct, just before a diffuser often leads to poor air distribution and increased noise.
Ceiling Diffuser may be round, rectangular, or linear slot diffusers (LSDs), for example. This last type takes the form of one or several long, narrow slots (hence the name), often semi-concealed in a fixed or suspended ceiling.
Occasionally, Ceiling Diffuser are used in reverse fashion, as air inlets or 'returns'. This is especially true for LSDs and 'perf' diffusers. But more commonly, air grilles are used as return or exhaust air inlets.
