Hi All,

I'm a new member and relatively new to climbing. I've done lots of hikes and small climbs in the northeast but i'm busy planning a trip to Aconcagua for December 2010 as i'd like to get some experience at altitude. Anyway I'll probably have some more questions, but i would like to say thanks for all those awesome trip reports and reviews that people have done. Very helpful for someone in my position.

As the title of this post suggest i've got a question about stoves. I've successfully used an MSR dragonfly for years with no trouble, i'm careful with my gear. However, i'm concerned about it's plastic parts for a trip like Aconcagua. People i've spoken to suggest using the XKG-EX or the Reactor OR both!! I'm fine using either or or both. I plan to be eating mostly dehydrated food, i really do enjoy it so i expect to be boiling water and melting snow. I'm thinking the Reactor would be the best choice for this, but how does a stove like this function at altitude with the lower pressure?

Any advice would be greatly appreciated.

Yours,
T

p.s. i did a cursory search of the forum and didn't notice this questions. if it's been asked already i apologize.

Do you already own a Dragonfly? If you do, why not just bring along a spare fuel pump in case yours break. From what I understand that's what most commonly breaks on the Dragonflys. MSR also has field service kits for their stoves that you could check out too.

Be careful with canister stoves as they don't work very well at high altitude. It works, just not as good. I used Whisperlite Int and it performed flawless, just make sure you bring extra fuel pump for your Dragon Fly (one of the pump got destroyed during mule transport).

even though most people recommend the XGK, I would go with the reactor... just be sure to keep the fuel cannisters warm. It is not a big deal.

We used a Dragonfly stove on Aconcagua. It worked flawlessly, just bring a few spare parts ie a spare pump. Cartridge stoves works well at altitude, due to the lower pressure of the surrounding air, but i think its easier to find good white gas than gas cartridges

Actually cannister stoves work better at higher altitude (its the pressure differential), but as mentioned, the cold does affect it. Not a big deal to deal with it.

First, DON'T insulate the cannister to keep it warm. The evaporation of the cannister as the gas is consumed, cools the cannister, and by insulating it, it will be counterproductive.

Second, while not necessary try using a heat exchanger for the cannister. It usually consists of a copper wire going through the flame and wraps around the cannister (don't use this trick if its not butt ugly cold since you can overheat the cannister.) Look online to get directions on doing this.

Note: piezoelectric starters (on stoves and in lighters DO NOT function well above 15,000ft and especially above 19,000ft. I always for get this and end up screwing myself so often.

Whisperlight has never let me down, plus I think they are more efficient.

squishy wrote:I love my Dragonfly, it's so loud, like me....

Those things are also great for scaring away the bears!

Wow thanks for the speedy replies!

I'm intrigued about the canister stove working well at altitude, i had read elsewhere that they don't function as well, but when i think about it the lower pressure outside would help i guess. Anyway sounds good with the dragon fly working well for those of you who had no problems. I'm familiar with the kits, and spare pumps, sounds like the way to go. Out of curiosity if any of you have been way up high on 8000m peaks what do you commonly use? I've seen lots of photos of canister stoves which i guess makes sense if you're primarily boiling water.

anyway thanks again for the help. I certainly know where to come for help. I'll be sure to provide a solid report when all is said and done.

I've been up Aco several times using Dragonfly stoves and have never had a problem. You might want to look carefully at the fuel you purchase however. El Refugio in Mendoza sells it in two liter plastic bottles that, at times, have sludge in the bottom that you wouldn't want in your fuel bottle. Also, don't tansport the fuel in the plastic bottles because they can develop leaks while being abused on the mule ride in. If you're climbing on the Vacas Valley side you can always find running water or large pools at the camps so you can take less fuel. On my last climb I only burned a little over 1 liter. As previously mentioned taking a spare pump and a rebuild kit is also a great idea. Wouldn't want to have to pack it in after all that planning and expense just because a cheap part failed.

Good luck on your climb.

squishy wrote:

CClaude wrote:Actually cannister stoves work better at higher altitude

That statement contradicts everything I've read or been told about canister stoves...

You been told wrong. As was said - they perform better at altitude due to the lower pressure. The problem is that they are affected quite badly by the cold, and typically when ascending the cold decreases performance more than the altitude improves things.

But, a heat-exchanger hooked to the bottle, an inverted canister, or a pressure-regulated stove (MSR Reactor) all help mitigate these, making canisters quite viable for anything these days.

That said, I don't own one. I still use my Whisperlite Int'l despite a slight weight and complication penalty because it's been reliable, and it's more versatile than a Reactor or Jetboil.

Canister stoves have been used very successfully on Aco, however, I have seen people run in to difficulty due to the quality of the gas available. Fellow Spers snocat and c-dog only had one good can at high camp and the others either didn't burn very well or ran out with a significant amount of fuel left in them. The temps that year were not very cold and they cooked in their vestibule so I don't think the cold was a factor for them.

squishy wrote:

Blakeman wrote:

squishy wrote:

CClaude wrote:Actually cannister stoves work better at higher altitude

That statement contradicts everything I've read or been told about canister stoves...

You got a source for this statement squishy? I believe that if you read further into everything that you have read regarding canister stoves, it says absolutely nothing in reference to the actual altitude and pressure being a negative factor in their operation. Rather, as CClaude indicated in his post, the cold found at altitude, will indeed reduce their effectiveness if not kept above freezing.

It's probably just the cold then...no no wait, I got it...what I am thinking about is water, it takes longer to boil water at higher elevations, thus using more fuel...but yet I know about the cold as well, I learned about that when my cold canister would barely run...you gotta put the fuel with your batteries in situations like that, down your pants...

high altitude = low pressure = low boiling point. Therefore water boils at a lower temperature, and therefore faster. It just takes longer to prepare food in it, since the temperature is lower. Next time take a physics textbook up on your climb.

That's why the Sherpa guides working of AAI take pressure cookers to high camp with them.

squishy wrote:

CClaude wrote:Actually cannister stoves work better at higher altitude

That statement contradicts everything I've read or been told about canister stoves...

Probably because PR agents, marketing writers, and journalists don't have engineering degrees.

The only thing that causes a problem for canister stoves is cold, since they generally rely on the vapor pressure of the liquid fuel to push gaseous fuel out of the nozzle. If the fuel gets too cold and won't vaporize, it doesn't feed gas to the nozzle. As you may be able to tell, the relative pressure pushing gas out of the cansiter will be the difference in internal pressure (which is a function of temperature and type/amount of gas remaining) and external temperature. If you drop the outside temp by ascending in altitude, the resulting difference in pressure is bigger. The confusion that most journalists and marketeers don't understand is that high altitude generally comes with an associated drop in temperature (which dramatically affects the internal pressure).

n-butane (like in your typical bic lighter or like what's mixed in a Primus fuel canister) boils at 32 deg F (0 deg C). This means if the canister hits below that temp, there is little or no n-butane gas boiling off the liquid in the canister to flow out the fuel line to the nozzle.

iso-butane (like in some high end lighters or what's mixed in Snow Peak ProIso, MSR IsoPro, Jetboil canisters, etc) boils around 12 deg F. This means canisters utilizing isobutane instead of n-butane work at lower temperatures.

Propane (like what's mixed in almost all common canisters to some concentration or what's present in those heavy steel green or white canisters for coleman stoves) boils around -40 deg F. This is what they use in northern michigan when they go ice fishing in the winter.

The colder you get, the lower the partial pressure for the fuels gets and the smaller the partial pressure relative to other components of the fuel, the less of that component gets boiled off and used in your stove. If you use a canister between the boiling points of the fuel components, you will eventually end up with a canister with no more propane to boil off and a bunch of liquid butane.

The Snow Peak ProIso canisters have a mixture of 65% isobutane and 35% propane. Other isobutane/propane mixture canisters are 70/30. This higher propane concentration means they will work longer/harder in colder temps.

Primus canisters are all but useless in cold weather situations becuase they use n-butane as their primary component.

There is a way to defeat the above problems to deal with ultra-cold conditions and that is to use a remote fuel canister with stoves such as the Jetboil Helios, Primus EtaPackLite, or similar stoves that have a pre-heat coil (fuel line goes through the flame) and the ability to invert the fuel canister. This means only liquid fuel is pushed out the nozzle of the canister, leaving gaseous propane (plus whatever amount of butane that boils off in your temperature application) to keep the canister pressurized.


Inverting the canister with something like a Brunton Stove Stand doesn't work well for stoves like the MSR Reactor or Primus EtaExpress because they don't have fuel pre-heat lines to vaporize the fuel before it gets to the regulator/nozzle. The reactor does still work better than some at low temperatures because its regulator seems to run at little lower pressure, so it's usable longer, but in use, the Reactor still loses power in cold unless you take measures to keep the canister warm.