Re: [VAC] CATALYST HEATERS

["terry c. tyler" <tylerbears@xxxxxxxxxxxxxx>]

Hi Tricia and Conrad,

Okay Guys, here's the skinny:
By now, you have read my earlier general reply. This reply is for specificity.  

Airstreams are not air tight by a long shot. They have a high level of natural infiltration with
outside air. A catalytic heater needs at least one square inch of FREE AIR opening per 1,000 Btu/hr
input to the heater when used in rooms of average tightness. The operative word is "average."
For the Olympian 6100 we use in our 22' Safari, that translates to about 7 square inches (an opening
3" by 3" equals 9 square inches). Hold your two index fingers at right angles and imagine a square
of that size. That is likely to be the general area represented by 7 square inches.

Vanessa suggested opening a couple of windows. That is perfectly acceptable. One window open 1/4" by
14" long equals 3 and 1/2 square inches. With the second window open 1/4 inch by 14" long, that
gives the recommended 7 square inches. Window lengths vary. I used 14" arbitrarily. 

Those of us with refrigerators on the floor with a hole underneath it for burner ventilation have it
easy. As a cursory guess, that area is at least as large as four of our imaginary 3" by 3" openings.
Combine that with high infiltration windows and the FREE AIR openings are profoundly more than the 7
square inches. 

Any additional efforts to increase FREE AIR are unrelated to the catalytic heater. Some people like
to let warm air (which rises) exit the trailer via a roof vent that's just barely cracked open. The
roof vent is not letting carbon monoxide outside because carbon monoxide is denser than air and does
not rise. It prefers low places.  

Those of us who don't like condensation forming on the roof vents and then dripping on us when we
walk around inside (giggling the trailer), have been known to open the roof vents. That is for a
different reason and we know that. We don't confuse it with the carbon monoxide considerations. 

I'm sure some of our purists will offer their more refined explanations, but this crude
understanding of what occurs has worked for us for 44 years in 8 different RVs. In all those years,
we have had cats traveling with us who slept in their bed on the floor. Every single one of those
cats was active and chipper in the morning after we used the catalytic heater before going to bed at
midnight or later and again in the morning before we got out of bed. Additionally, this included
using the propane light and the burners on the stove for making hot drinks. We never once restricted
our use of propane because of concern about carbon monoxide. We believe we understand the potential
problem. We believe we have taken measured precautions. And, for us, the proof has been self
evident. 

Bottom line, use your catalytic heater wisely and let it provide the comfort you need to make living
in your Airstream a pleasant experience - anywhere on the continent. 

Terry