on a related note, with regards to a co2 detector, how would you know if it was a false alarm or not?
Not to be nit picky, but CO2 is Carbon Dioxide. It's what you breath out. If you had one of those you'd be having frequent alarms (like on every exhale)
CO3 is carbon monoxide.
By the way, we installed some cheapo smoke alarms and they are the most sensitive things I have every seen, or heard. We open the oven, beeeep, we take a pot off the burner, beeeep. I guess it's better to be sensitive than not,but it is annoying.