In article , "Joseph Meehan" wrote:
I have heard this one both ways. While I would think that most sources
of CO will be be heat producing sources and as such the warm air would force
the CO to rise quickly.

This is correct...

CO is lighter than air and will tend to rise.

... but this is not. The density of air is 1.29 grams/liter; that of CO, 1.25.
This is not a significant difference: the density of nitrogen is *also* 1.25
grams/liter, and air doesn't separate with nitrogen at the top, and oxygen
(1.4 g/l) at the bottom.

I have had one personal encounter with CO. In that case the CO
concentrations were decently greater at five feet than at four feet and
greater at four feet than one foot.

Undoubtedly because it was warmer than the air, and hence less dense.

Glad nobody suffered any permanent ill effects.

--
Regards,
Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt.
And who wants to leave buttprints in the sands of time?