We moved into a new(er) house a few months ago and as I go through checking things out more I started researching co2 detectors as ours is in the basement. I'm finding some information that says they should be in the hallway outside the bedrooms and other sources says one on each floor like the smoke detectors. I'm wondering where is the best place?
We have a 4 level split house and there are smoke detectors in each level and they are hardwired to a dedicated circuit with 9v batter backup. I was thinking of getting a hardwired co2 detector and adding to that circuit then put a UPS after the breaker so were not relying on 9v batteries ( though I do change them). I also noticed when we set one off while cooking it sounded like all 4 went off. I'm wondering if they transmit a signal across the electric line like the x10 stuff. If I should have more than one co2 detector are there ones I can buy that are hard wired, or possibly a combines co2/smoke detector to replace the existing? Are there ones out there that can set all off is one goes off?