Diffusers & Grilles

• Use 12x24 RA grilles in small rooms. 24x24 overpower the look of the ceiling.

• When using supply slot diffusers for returns, use the same diffuser, but tag and schedule as ‘Rx’.

• Only use 6”ø diffusers in areas that will not change in the future. Storage rooms, small offices (100 CFM or less), etc. are okay. Do not use in open office areas where airflow requirements could change in the future.

• Perforated return air grilles: 24x12; 0-600 CFM max., 24x24; 600-1000 CFM max.

• Use 12x12 diffusers in lay-in ceilings for airflows of 75 CFM or less.  You won't get any throw out of a 24x24 at that low of an airflow.