Louvered square diffusers, round cones, perforated faces, linear slots and swirl diffusers each give a different pattern and throw. Good diffusers induce room air into the jet, so cold supply air is tempered before it reaches people. Picking diffusers is about cfm, throw, pressure drop and noise rating, and a wrong pick shows up as drafts, dumping or noise.
Diffuser in the conference room is dumping cold air straight down, swap it for a slot with better throw.
Also heard as
- supply diffuser
Do not mix it up with
- Register: A diffuser spreads air in a pattern; a register is a grille with a damper behind it, typically on a wall or floor.
Related terms
Throw
How far a supply air jet reaches into a room before it slows to a chosen speed, such as 50 feet per minute.
Register
A supply or return grille fitted with a damper so its airflow can be adjusted or shut off.
CFM
Cubic feet per minute: the standard unit of airflow through equipment, ducts and outlets.
VAV
Variable air volume: a system that holds supply air temperature steady and varies the amount of air to each zone.