smoke detector locations?

[JimS]

I have line powered, interconnected smoke detectors but want to add detectors tied into the existing alarm system.  My only question is where?  The existing detectors are in each bedroom and outside each bedroom (in accordance with local rules).  I could place one in each of these locations but that seems like overkill.  I am thinking in the equipment rooms - I have two in walkout basement, one has furnace on one side of the house and one has gas water heater, and electronics "closet" on the other side.  Then one for the main (only other) floor.  That seems like a reasonable minimum.  I have 6 existing with two bedrooms on each floor.  Could also put one in garage but may want heat sensor there.
 
Any issue interconnecting 4 wire smokes with heat sensors?  Recommendations on models and where to get?  I have a couple 20 year old unused 4 wire units (think they came from radio shack).  Any issue with mixing 4 wire brands or age?  I have seen some places state they should be replaced after 10 years.
 
Any recommendations on locations?  Have decided not to connect existing detectors to the panel for fire, although I might connect them some other way for personal notification and automation.

 

[dougmeredith]

I faced the same issue, but hated the idea of doubling up on the detectors.  In the end, we tied a relay onto the existing detectors, and used that as an input to a zone on the alarm panel.

 

[JimS]

Unfortunately, both your replies missed the point - sorry if I didn't make it clear.  I have read numerous threads about the pros and cons of connecting line powered detectors to the alarm panel and I have no interest in rehasing that aspect.   My question is if I add additional detectors designed to be connected to a panel (which is what I plan to do) where should I be installing the additional detectors?  The line powered type are mainly for alerting occupants so they can escape the fire.  The panel connected devices are for alerting fire department to hopefully put out the fire before everything is destroyed.  Thus it seems more effective to place the panel connected devices in places where fires are more likely to start.  I haven't researched this lately but I think that would be furnace room, garage, etc rather than bedrooms.  Without going into the layout of my house in detail, what is reasonable for number and placement?  I realize this is a highly subjective question.
 
If the panel connected alarms aren't put in bedrooms then perhaps some way should be made to activate sounders in the bedrooms but that can be handled in a number of ways I can think about later.
 
Since the garage wasn't required for the line powered detectors I think adding something in the garage would be good but what type?  Since fumes are sometimes an issue in a garage I think temp sensors are recommended.  They won't false but also won't respond as quickly - just a trade off that can't be avoided AFAIK.
 
If anyone has any recommendations on where to buy that would be good too.  Of course there are many on line places...

 

[Del91574]

While subjective, if installing redundant spot type detection, my vote is to install the former code requirement, one on each floor, centrally located.
 
For garages and "dirty" utility spaces, heat detectors are what's needed, not smoke detectors.