Where to place smokes/heat?

[canyonblue@xxxxxxxxx]

I have a new construction house with at least 7 120v wired smoke
detectors placed throughout (4 bedrooms + 1 each of the 3 levels). If
one goes off they all go off. I am adding an extensive ADT system and
don't necessarily want to duplicate the extent of the current smokes,
but would like a reasonable effective agumentation to the system.

I am thinking 3-4 smokes or heats, 1 on each level with perhaps an
extra heat near the furnances in the basement. Where physically should
smokes go and where do you suggest a heat sensor instead? Thanks...