Combo smoke/CO devices are a bad idea to begin with; smoke rises CO/CO2 is heavier than air so it sinks. I'd never use them
This is misinformation. Co detectors can be mounted on walls, or ceilings, up high or down low. It does not matter because carbon monoxide is only slightly more dense than air it mixes in with the air quite well so location of the detector does not matter.
What I wonder about the combo units is if it creates confusion if it's a fire of CO leak. I know they have some now that talk while I think the others had lights.
We did them interconected with the somkes as combo units and seperate units with their own switch leg only to CO. I like the 2nd way better. Seems like the more you interconect the harder it is to find the bad one.
Most places here don't have CO requirements so it's a upsell or just on the print.
