Smoke detector spacing

[Birdem]

Anybody?

[Leo]

21 ft is all you need to know.

a smoke must be within 21" of any wall, you will find it within NFPA72

[Birdem]

Alittle off topic but would far would a heat detector have to be located from a sprinkler head

[Leo]

"heat detector have to be located from a sprinkler head"
what is its application?
is in an elevator shaft
preaction system
or just an open area sprinkler head.
if open area I know of no code, why do you ask?

[Birdem]

They have sprinklers in the elevator machine room do not ask me why. They would like heat detectors to report to the facp and of course send the fire department if anything was to ever happen in there. Thats is why I was asking how far would a heat detector would have to be from a sprinkler head. I know some building do not even require a heat next to a sprinkler head or maybe thats a grandfather code.

[Birdem]

Hello can someone be more detailed about the smoke detector spacing. I understand 0.7 times listed spacing will tell you the radius or coverage of the smoke detector... I need a formula for different type of rooms rectangle or octagon shaped rooms how does the calculations change. how else does it change with beams and joists in a specific room. Thank you in advanced.