My heater is an inside-the-van air eater and inside-the-van exhauster. It
eats the internal air and contaminates that environment with potentially
deadly gases.
A feature of CO, it is heavier than air so drops to the floor of the van,
which is why the detector should be near the floor. Mine is on the front
face of the rear bench, just below the bed where CO would likely get trapped
directly across "the room" from the heater, mounted on the battery panel
behind the passenger seat. Using these in tents while sleeping on the floor
makes them deadlier. In the van we're up high enough to avert this exposure
and opening windows and the skylight vent a little has resulted in my
awakening in the morning for the last several years.
My experiences with these heaters has been in VW campers, and dropping the
top at night and keeping it down on cold mornings makes a bigger difference
than anything else. I'm a single guy and most of my trips are just me so
it's an easy accommodation.
The installation of the propex puts both the intake and exhaust pipes/hoses
within about a foot of each other under the van, and if the intake sucks
exhaust it is going to cycle through the heater, not into the van. It also
exhausts to the outside air and is exposed to that environment, and drops.
I still think the detector is a very good safety measure.

Bob

> Thank you, that is exactly what I thought.
>
> Randy
>
>
> >Carbon Monoxide is a product of all combustion. Since the exhaust for
> >the Propex is still under or close to the van, no way I would use one
> >while sleeping without the CO detector.
> >
> >Dennis
> >
> >Does propane when burned (used through a heater) give off carbon
> >minoxide? I just put in the propex heater which is externally vented,
> >but wanted to put in a battery operated detector for safety. Then I got
> >to thinking. Is carbon Minoxide a byproduct of propane??
> >
> >Randy
> >87 Syncro