catalytic heaters?

[arlon]

Just discovered these things. Has anyone used them in a van? They sound like they would be safe to use but nothing really comes out and says how they would perform in a closed van. Also haven't found anything about how long they last on a propane bottle. Any input on these things as applied to use in a camper van would be appreciated.

 

[Patman]

Lots of people use them, but they are not safe to just leave on in an unventilated space. Most people I know use them to heat up in the am with a vent open. Some of the "buddy" heaters have built in O2 sensors, but they do not address CO. I have a small one that mounts to a propane tank and have used it for a tent heater on several occasions. But never more than a few minutes in the morning before getting up. Just to take the edge off.

Depending on what you read and believe, as long as the O2 use of the burning propane is addressed (open vent or window) they should be safe for extended use, but I would at the very least have a LOUD alarm for CO and low O2, but I can be paranoid too!

 

[Token]

CO.. Please.. When I was growing up we'd go camping in summer and the temps during the night wouldn't drop below 90 sometimes at night.. We'd get a big block of dry ice, put it in the cooler in the middle of the tent and sleep great...

FWIW.. I've got a Colman Sportster Catalytic that I hang up in my RTT and have ran it all night with the doors and windows closed and had no problems.. But it's a tent and it does breath a little bit and there are vents on each end at the top.. In a van, I'd leave a window cracked down about 2 inches or so and sleep off the bottom of the van since CO being heavier than the stuff we typically breath, will settle to the bottom..

 

[mhiscox]

There's been a discussion of much of this at:

http://www.expeditionportal.com/forum/threads/69920.

Also, it's worth noting that the rule of thumb for ventilation of a cat heater is one square inch for each 1000 BTUs of heat, so it's usually pretty easy to meet the ventilation requirement.

 

[Bbasso]

fairly close to the heater you're asking about...
I have the mr buddy heater for a few years, I open each of the front windows to the bottom of the rain guards and have a small 12v fan to circulate the air.
I'm still here and have spent plenty of warm nights inside my van. I believe the key is to move the air inside to prevent pooling of bad stuff.
I would think that more BTUs equals larger window opening.

 

[Photomike]

I use a Mr Buddy and like it. Yes you do need to have a source of air when running. If you want a cat that does not need air you can get vented units, if I had the space that is the way I would go.

 

[Herbie]

CO.. Please.. When I was growing up we'd go camping in summer and the temps during the night wouldn't drop below 90 sometimes at night.. We'd get a big block of dry ice, put it in the cooler in the middle of the tent and sleep great...

Leaving the anecdotal evidence aside, I feel it's very important to put out the chemistry at work here:

Dry ice sublimates to CO2 (Carbon Dioxide). The danger with Catalytic heaters (and other open combustion types) is CO (Carbon Monoxide). We're not talking about suffocation here. CO2 is really only harmful if it exists in such high quantities that it crowds out the oxygen the body needs. CO, on the other hand is POISON. Only relatively small concentrations are required to render anything from headaches and nausia all the way to coma or death.

All combustion produces some CO. In an unventilated space, as the O2 is consumed the proportion of CO (to CO2) that gets produced can shoot WAY up. (sort of a feedback loop.) THAT is the danger of such devices.

That said, I wouldn't sleep in an enclosed space with dry ice either, but that's not really what were talking about here.

 

[mhiscox]

Should anyone prefer to fully understand the situation, rather than presenting as fact what might (admittedly) seem a reasonable guess, read this report by U.S. Consumer Products Safety Commission:

http://www.cpsc.gov/library/foia/foia05/os/co03.pdf.

-----

And for the vast majority of you who aren't interested in reading the report, here are the two most salient findings from the report's conclusions:

The peak CO concentration ranged from 68 ppm to 125 ppm and the steady state CO concentration ranged from 67 ppm to 109 ppm. Assuming a limited exposure time of up to 6.5 hours at these CO concentrations, the catalytic heater does not appear to pose a serious CO hazard to healthy adults when the CO concentration is considered by itself.

and

When the catalytic heater was operated in a closed room (ACH ~ 0), the oxygen was depleted from an ambient concentration of 20.9 percent to 8.8 percent. Because the catalytic heater can deplete the O2 concentration to such low levels, the heater poses a serious risk of hypoxia. The degree of hypoxia is further exacerbated by the moderate CO concentration and by an increase in the carbon dioxide concentration that accompanied the depletion of oxygen.

 

[Desert Dan]

They work pretty well.
Just keep a window cracked open.


No sleeping pills needed!

 

[arlon]

Thanks for all the info. I've decided to get one of the small units with O2 sensor and add some small amount of forced air (12v cooling fan venting from the bottom of the van) and crack the windows a little. I did my first weekend in the van and it was only 38 deg and pretty comfy really. Maybe only need it for a few hrs a night during the dead of winter down here.