• Welcome to the new and improved Building Code Forum. We appreciate you being here and hope that you are getting the information that you need concerning all codes of the building trades. This is a free forum to the public due to the generosity of the Sawhorses, Corporate Supporters and Supporters who have upgraded their accounts. If you would like to have improved access to the forum please upgrade to Sawhorse by first logging in then clicking here: Upgrades

Return air distance from sprinkler head

chris kennedy

chris kennedy

Sawhorse
Joined
Oct 24, 2009
Messages
1,538
Location
Miami Fla
I was told today that a return air opening must be 3' from a fire sprinkler head. Makes sense to me but can't find the art.

Little help please.

Thanks
 
It is in NFPA 13

Can give a section Monday

Another option is to use a higher temp head, if it needs to be less than three feet
 
Do you need this for

Commercial or residential??


Also what edition of 13 and 13 R are you under
 
Last edited:
Will look on Monday


More than likely the link and chart above is what I will find


Which edition of 13 would you like
 
In the 2016 NFPA 13

Check section 8.3.2.4 and 8.3.2.5 with tables

And one option in some cases is to change the sprinkler temp to higher level
 
I can see the need to locate a smoke detector a distance from a return grille, because the grille might pull air away from the detector.

A return grille is pulling room temperature air, so I don't see how it would affect sprinkler operation.
 
cda said:
In the 2016 NFPA 13

Check section 8.3.2.4 and 8.3.2.5 with tables

And one option in some cases is to change the sprinkler temp to higher level
Click to expand...
That's for diffusers though. I'm not finding anything about return air openings...It makes sense you would want to locate them away to ensure that the heat is not being pulled from the area and preventing the sprinkler from discharging until the fire has increased in size beyond where a single head will be able to contain...
 
I guess I should read each word.

Will look again, but have not heard of a distance requirement for return air.

Unless there is a tremendous velocity, I am thinking the heat plume will activate the sprinkler, even with the hvac going
 
Probably. I'm just worried about the buoyancy of the hotter air being the one that gets removed first and is replaced by cooler air around the head.
 
If there is enough fire to activate the sprinkler,

There is enough fire to activate the sprinkler.

Plus you also get into spacing, there may be a sprinkler nearby that might activate, if the return air is messing things up.
 
As with sprinkler jumping, would you not have portions of the fire potentially outside of the spray of the head in this scenario? Isn't this why there are minimum head spacings? Not being sarcastic, I'm honestly asking. I know enough about NFPA 13 to be dangerous, not helpful.
 
I would say minimum is so one does not spray on another, depending where you apply minimum

Such as four inch minimum away from a wall

I do not think return air vents are normally a problem
 
You must log in or register to reply here.
Top