in the process of remodelling my basement, i'm upgrading the alarm system as well, primarily to increase the number of monitored zones because of added points of entry, and since they'll be out anyway, i'm looking at adding smoke/heat detectors. currently i have one smoke detector, centrally located upstairs and one heat detector in the basement laundry room. i'm adding one detector in each bedroom upstairs (not required but it seems prudent), one in the basement office (back half of the house), a heat detector in the garage and one in the basement den. the den is 13' x 24' and the ceiling is 8' high. running down the middle of room (cutting the 24' dimension in half) is a heating duct (approx 18" wide and 10" high) that sits below the bottom of the joist line. this duct has been framed and will be sheetrocked while the rest of the den will be a drop ceiling, about 2" below the joist line.
here's my question. do I need to have one smoke detector on each side of the duct or would one, centrally located, on the bottom of the heating duct chase be sufficient? if smoke were travelling up and across the duct area it would be detected right away, but if the fire started in one of corners and went straight up, it would have to fill that 10" cavity space before crossing the duct to set it off. and since i'm using a drop ceiling, if i did put on on each side, i'd have to do a veritcal mount on a wall, which means if a fire starts on an opposite walll, there would still be a necessity to fill the cavity, although not as much.
Thanks
B
here's my question. do I need to have one smoke detector on each side of the duct or would one, centrally located, on the bottom of the heating duct chase be sufficient? if smoke were travelling up and across the duct area it would be detected right away, but if the fire started in one of corners and went straight up, it would have to fill that 10" cavity space before crossing the duct to set it off. and since i'm using a drop ceiling, if i did put on on each side, i'd have to do a veritcal mount on a wall, which means if a fire starts on an opposite walll, there would still be a necessity to fill the cavity, although not as much.
Thanks
B