Table 8.3.2.5 (a)

[FIVE50]

In regards to a ceiling diffuser in Acoustical ceiling. Would that fall under downward discharge? I’m trying to understand if you can have a ordinary temp. 155 degree. 1 foot away? Basically in the center of the 2x2 tile next to the diffuser tile.

 

[UFT12]

You will need to clarify with the HVAC system designer whether the diffuser is of horizontal or vertical discharge. A.8.3.2.5 provides some clarification. Also Table 8.3.2.5(a) says within the first 1' or 2'-6" from diffuser edge, depending on discharge, sprinklers must be of intermediate temp. classification unless the air temperature does not exceed 100F/38C. The commentary also clarifies that the distances be measured from the outer edge of the heater/duct/diffuser.

 

[FIVE50]

Downward discharge: Cylinder
with 1 ft 0 in. (300 mm)
radius from edge
extending 1 ft 0 in. below
and 2 ft 6 in. (750 mm)
above

 

[FIVE50]

 

[FIVE50]

So I’m taking it as that’s a downward discharge diffuser. So from the edge of the vent on the diffuser how far would everyone keep a ordinary 155 head ?