In episode 1602, Scott installed six or seven new smoke detectors in a home in North Carolina. It was later mentioned that the detectors incorporate carbon monoxide detectors. I'm writing to ask what possible value such detectors have when mounted on a ceiling. CO is heavier than air, and if it is detected near a ceiling, the entire room would have to be full of CO, and any occupants would already be dead.
One would think that the manufacturers would be aware of these facts, and not bother putting CO detectors in ceiling-mounted units.