Recommendations for smokes


All - Im looking at expanding my Elk M1 system to include smokes and CO2. My house is rather large and between the bedrooms, basement, 1st, 2nd floor and attic I figure I am looking at about 12 smokes needed.

Ive read a number of posts debating the 2 wire vs 4 wire setup and Im looking for a recommendation on what might meet my needs. I understand that with 4 wire I will need supervision on the power as well as alarm wiring. I trade off this complexity with what looks like best practice in having each floor on a separate zone. If I want the 4 floors on their own zone, my M1G only allows 2 wire on 1 zone, zone 16. Am I locked into 4 wire in this case? Obviously I will be daisy chaining each zone no matter what and I do want to keep with local code having all units sound in an alarm.

Also, can anyone also recommend what brand and model has worked well with their Elk system? Id like to have sounders in each unit and possibly mix in some heat and smoke units.

Thanks in advance!
If you want smoke and CO detection, look at the i4 series from System Sensor.  There are 2-wire and 4-wire models.
To get the full benefit of the CO detection, you should use them with COSMODxW modules, which break out separate smoke and CO signals for connection to separate zones.
With the COSMOD2W module, you wire up 2-wire smoke/CO detectors, but from the panel's point of view, the COSMOD2W connects as if you were using 4-wire detectors.  So you can wire up multiple COSMOD2Ws, one for each floor, but still have most of simplicity of wiring 2-wire smokes.
If you do use 2-wire smokes, you won't be able to put heat detectors on the same loop.  You would need to run a separate zone for the heat detectors.
With 4-wire smokes, you can put heat detectors on the same zone.   The disadvantage of the COSMOD4W though is that you lose the maintenance signal output.

If you are going to go down the path of having multiple detector zones, be prepared for a good amount of complexity to achieve tandem ring across all the zones and being able to properly reset things after an alarm. 
One other thing - don't put smoke detectors in the attic.  They just don't belong there and are not recommended for that purpose.  Use heat detectors instead.
Thanks RAL. I should clarify that i was going to wire and put the CO2 detectors on their own zone and keep them completely separate from the smokes. Thanks for letting me know that the heat detectors need to be on their own if I do 2 wire and that the attic should get heat only.

Sounds like from you point of view a 2 wire setup would be the way to go though despite the number of floors and modules?
kxcntry99 said:
Sounds like from you point of view a 2 wire setup would be the way to go though despite the number of floors and modules?
My preference would be to use the 2-wire smokes with a COSMOD2W if you want to have multiple zones.
If you are looking for standalone CO detectors, System Sensor also has those.  But they require 6-wire connections to form the daisy chain.  Using the combo smoke/CO detectors simplifies the wiring vs using standalone detectors.  If you want smoke-only detectors, then consider the i3 series.