How do you handle the risk of carbon monoxide poisoning?

I guess this applies to those who use carbon-based fuel-stoves within an enclosed space like a small cabin, boat, tent or teepee.
There are many good sites that reflects around the issue, i.e. Roger Caffin at www.backpackinglight.com.
A few years back I did my own measurments on some active wood-pellet stoves, spiritburners and modern (splitted hose) multifuel stoves.
One of the most popular choices of the novice-camper here in Scandinavia would be the Trangia spiritburner-kits. It is thus a paradox that these passive stoves emits more CM than most pressure stoves around. That said - I have often had the 1500W spiritstove Origo Heatpal running unnatended through the night in our teepee. It is merely a question of understanding the risks and then deal with them properly.
The modern kettles with heat exchangers adds to that risk by doing what they should - sucking energy from the flame, thus lowering the combustion temperature through a longer period of the (snow)melting/cooking sequence. As a rule of thumb the CM emmisions incrases by a ten-fold vs a std flat-panned kettle.
Add a spiritburner to that and zipp the tent, you might have a life threatening situation in hand.

Are there any of you guys who have own experiences or thoughts to share?

 

Always an important thing to keep in mind. My dad always believed in lots of fresh air. He would fill the stove with wood then throw open the doors in the winter,much to my dismay since I had to fill the wood box. But it kept us healthy, and I still do the same today, a good lesson.
Ivan

 

I use my stove outside or just outside my tent door. One time I did use the stove for a few minutes inside to warm it up a little as a treat to myself. They do need to be started outside to avoid flareups. Even I don't take a chance of killing myself with using a stove inside a enclosed structure. I snowcamp in the winter, often in sub-zero F temps and use my stoves outside.
Duane

 

Death from carbon monoxide buildup inside tents is extremely rare. Unless you're running a poorly burning unvented stove for a long time inside a tightly sealed tent you probably won't have a problem. If you are concerned a portable carbon monoxide monitor with an alarm will ease your mind.

Ben

 

Ben, we would have to discuss "rare". Googling the issue it would seem that CM deaths is certainly a problem world wide i.e 40 deaths/200 hospiltalisations pr. year in the UK alone. Tents, campers and boats seem to be highly represented in these statistics. Also disposable charcoal grills are disasterous CM generators - thus they have even been used as a mean of intentional murder Statistically I agree that if you consider the nr of deaths or accidents up against the total of travels/hikes spendt in such lodgings, you are right. The fact that an inexperienced person would consider going to sleep with that grill inside the tent is disturbing, but understandable. It is a matter of knowledge that they have not yet aquired.
Highly skilled adventurers have failed to recognize the hazard kettles with heat-exchangers introduces, thus utilizing their stoves in their tents as in previous expeditions, which almost costed their lives.

 

I wonder what the stats would be without the charcoal grills....those are major killers here, too, but mostly not "camping"...

 

Carbon monoxide is a flammable gas and with adequate oxygen it burns to form harmless carbon dioxide even using heat exchange kettles. At lower elevations stoves are pretty efficient and produce little carbon monoxide. Three season tents aren't very well sealed either. Under normal circumstances using a propane, gasoline, kerosene, or Trangia alcohol stove to cook a meal inside a tent shouldn't cause concern.

At higher elevations it's a lack of oxygen that makes heat exchange kettles dangerous. Insufficient oxygen results in incomplete combustion which means more carbon monoxide in the fumes a stove gives off. If those fumes are cooled by a heat exchanger before the carbon monoxide has a chance to burn it can build up to dangerous levels in a tightly sealed four season tent. This is especially true if the stove is run for an extended period to melt snow in a heat exchange kettle.

Burning charcoal or wood in a tent without venting the fumes outside is just plain stupid under all circumstances.

Ben

 

Admiral R.E. Byrd was very nearly asphyxiated at Advanced Base meterological station, Antarctica, in 1934. He was working solo for 5 months. [Not sure of the brand of stove.] When his radio transmissions to Little America Base Camp were garbled, his comrades got alarmed, but 2 attempts to mount a rescue were thwarted by mechanical failure, snowstorms and darkness. Finally, they got thru and found Byrd in poor health, and a few days later Byrd and the doctor were flown out to base camp.

 

Here is a report from a field study carried out in Norway on 2004 - published in " American Journal of Emergency Medicine" http://scholar.google.no/scholar_ur...=0ahUKEwjs3pP088nQAhVGMZoKHeRQBZ0QgAMIDCgAMAA Stove used is an Optimus 111

Another study made by the Norweguan Defence Research Labratory in 1997 suggests that while the CM levels from an "unpottet" stove are modest, adding a cold kettle results in a 10 X increase of CM emission. The study from 2004 supports they are significant.

A follow up study from 2012 indicates a further 10 X CM increase using a kettle with heat exchanger - in sum a 100 X increase

The 1997 report indicates an alarmingly high CM emission from the Coleman 445, not so much from the 111, and the cleanest comb had an MSR XGK II. The Norwegian Army has btw recently procured the MSR XGK EX as their new stove. Which is what I got my flyfishingaddictofason instead of a (then) troublesome 8R. Which could mean that there will be a new flood of surplus 111's hitting somewhere soon.

 

One time in the history of the MSR XGK stove the pot stands were purposely lifted/lengthened to reduce CM, and the efficiency was reduced as a result.

 

@haknuts You mentioned using a stove in a teepee.

A teepee (one with a liner, anyway) is basically a chimney. When we had ours set up, we used a sheepherder (wood) stove with a 4-foot section of stovepipe (containing a spark arrester). (USFS would not permit open fires, even in an enclosed space.) Obviously, the stovepipe came nowhere near getting outside the teepee. Hot air (and CO and smoke) rises. If there is a way for it to escape (like open teepee flaps) it will, especially if the outer layer of the teepee isn't sealed to the ground. I admit, when we stayed in ours I didn't fully trust the logic or the thousands of years experience of people living in such shelters, so we had a CO monitor. Not surprisingly, the alarm never sounded. (One rule with a teepee: if it's raining hard enough that you close the smoke flaps, you have to put out the fire!)

When I use a campstove in the house, I always set it on the kitchen stove, under a range hood that vents outside. Better safe than sorry. Lately, I've been thinking of using a Beatrice for occasional tea making in a small house without a kitchen. If I do this, I will definitely have a CO monitor nearby.

....Arch

 

Last people I know of in NZ to die accidentally from CO did so by moving an outdoors patio heater running on propane into the house on a cold night. Exit one family.
A few years ago a couple of Doc workers did themselves in by using a butane stove in a small tent The stove was missing its trivit so pot was resting on the burner.Doc are the guardians of our outdoors so these two should of known better.
Knowing how to control ventilation to combat co poisoning should be up there in the skills base with knowing to fill your stove well away from the cooking

 

At all time the stove is lit inside my tent, I ensure that I always have good ventilation. When smelting snow, and the CO-production is on its worse, I sit with the face in the tent opening, so I am sure I breath fresh air.

Knowing the symptoms like headache and knowing fresh air is the cure will also help if the CO-consetration is too high.

Even if CO is odorless, incomplete combustion may be recognize by smell of the fuel and exhaust. With this smell, one also know CO will be present. When heating cold water in pot with heat exchanger, I have no problem sensing this. My own experience combined with the report from FFI ( http://www.ffi.no/no/Rapporter/2012-00404.pdf ), is enough that I do not use this pot inisde my tent.

Under no circumstances I will let a stove be lit when I am sleeping. Not only because of the CO-danger, but also because of the fire hazard.

The Trangia spirit burner with its unvisible flames and danger of spilling burning spirit if one bump into the stove, are to dangerous to be used in or near the tent. CO is the very least danger with that burner.

 

Over the years I have figured out it is best not to use a stove like a 00 a 111 or even the smaller 96 or 123, inside a small hiking tent. With small hiking tent, I mean lightweight one or two person tents mostly used by one person. The distances is simply too small, the flame will be too close to the fabric. A Trangia is out of the question because I do not like or trust the stupid burner.

The only exception is if one fixes the tent “door” securely open, and thus get enough distance between fabric and flame. I am then outside the tent. I usually bring a tarp and does all the stove use under it. If I use a big enough tent or a lavvo/tipi, I uses both pressure stoves and wood stoves inside. It is all about volume and ventilation.

The thing that I find is dangerous is if one changes something – changes the routine – change in wind/weather and the general conditions, snowfall will for example insulate and possible cut ventilation. Starting to use a heat exchanging pot is mentioned above, or it could be bringing a stove into a tent for the first time.

Another example is I have started to use the Speedster stoves a lot. They are very secure in every way regarding fire hazard, but is still open flame and will produce some CO. I am actually now using those inside a tiny tent. I have taken it very step by step, and make sure the ventilation is open max.


I did a test out on the island at my holiday home. I have a CO alarm there (looks like a fire/smoke alarm) because I use a paraffin heater. The bathroom is small (about 1.80 x 2.40) and I stopped the vent fan, so very confined. First I lit two Speedster stoves and let them burn empty. It took 20 min or so, and no reaction. Then after airing a bit I lit a 00 and the CO alarm went off in about a minute – quite the difference but very unscientific. One could feel the discomfort right away with the 00. (I had pots on all burners.)

I often have both the paraffin heater and a stove going in the living room/kitchen under normal ventilation, and the alarm do not react on that.


All the best, e

 

Thank you all for your contributions. With regard to keep heating a teepee through the night I will add that the mentioned HeatPal has a spill-proof spirit burner-canister as shown here. It is fastened within the aluminum cage as shown above and takes some efford to tip over. Even if so it will not spill fuel.


While my own measurements shows the HeatPal emitts more CM than an efficient modern expedition stove (unpotted), the chimney design of a teepee, as pointed out by Arch, makes it a safe stay.

The test I did was actually carried out in a large top-vented teepee, and it was not possible to measure CM buildup readings inside. I had to place the sensor in the stoves upgoing airstream, and so I could only measure the relative differences between the candidates.

The native Norwegian Samipeople have had their teepee's (lavvo) heated with a central open woodfire for centuries. It is a wellproven great design.

 

When camping on snow, there are opportunities to make headroom greater, or more precisely, make the floor lower. I use to have almost standing room in the vestibule.

 

A great topic.

My understanding of teepees are that the opening is never closed all the way, and any rain that does get in is supposed to follow the inside wall or pole all the way to the ground. No bumps on the pole to allow dripping.

On CO from heat exchanger pots, I see now it makes sense to not have the stove turned up high.

Ken in NC

 

I have often been dismayed at the suggestions by some so-called survivalists (always on other forums, youtube, etc.) who advocate for open alcohol burners in enclosed spaces, including vehicles, based on the misconception they use a "natural" fuel and thus produce no toxic products or CO.

 

I think you need to explain that a bit more for those not used to camping in a lot of snow...
Edit: I tried to find a diagram of a "snøhule" layout, but no luck so far

 

@afoton @janders

Good point I have done the same, I was thinking how to explain but my English is not good enough. A knee deep (dig down in the snow, typically used in an igloo as a cold air trap) tent vestibule helps for fire but CO is still a risk.