Just wanted to add my voice in saying I thought this was a fantastic article, deciphering and explaining something that affects anyone using a canister stove. I look forward to using this practical information to ensure I don't go without coffee on a cold morning ever again, wondering what the heck is up with my stove and it's full fuel canister.
Thanks for taking the time to research and post this, there is great value in it for me.

Great article! Thanks for the clear details and charts.


Jim wrote:
>2. For temps between -40C (-40F) and -10C (+14F) use 100% propane and accept a substantial weight penalty.
>
>3. For temps between -10C (+14F) and 0C (32F) [...], or use a stove designed to burn canister fuel fed to it as liquid

Since gas-phase propane provides the majority of the pressure in a canister, liquid-fed stoves can work to temperatures well below +14F. I think the recommendation to use a liquid-fed stove should move from range 3 to range 2. I've used my Coleman Exponent Xtreme at -30C (-25F), although when it's that cold out I pack the canister in snow to keep it warm.

Edited by Otter on 10/27/2010 11:48:57 MDT.

Very interesting!
I have for some years experimented with top-mounted canister stoves in winter here in Sweden. I have found one method that works very well. During the day I ski with the canister in my anorak chest pocket. During the night I put the canister in my sleeping bag. No problem what so ever using the stove at -20--25C (-5F).
It is useful to have a cosy of closed cell foam around the canister as long as the canister itself is warmer than the surroundings. Sounds a bit tricky, but I do not cook for long so the canister seldom gets very cold.
Using a canister stove this way makes it very simple to sit up in your sleeping bag on a really cold morning and cook in your tent.

> 6.5*C/km gained is equivalent to about 4*F/1000ft
6.5 C = 11.7 F
1000 m = 3,281'
so 6.5 C/1000 m = 11.7 / 3281 = 3.566 F/1000'
That figure is a generalisation of course.

Does the starting altitude have any effect? Not a lot pre se, but I would imagine local conditions will play a far larger part in this.

Cheers

Thanks Jim :-)

However, I do not agree with point 2:
> For temps between -40C (-40F) and -10C (+14F) use 100% propane and
> accept a substantial weight penalty.
My reason is that I have cooked below -10 C many times quite happily.

During the day I keep the canister in my pack next to my water bottles, which are close to my back. That means the canister never gets *too* cold, as the water bottles don't freeze. A good use for body heat which should not be ignored.

I always use a liquid-feed stove in winter, and they can run with a canister temperature down to about -24 C. Not strongly, but they can get going. As I usually manage to keep the canister warmer than the environment, this lower limit is not very limiting in practice/

I leave the canister exposed to the flame radiation and maybe sitting in a bowl of cool water - which is above 0 C of course. This means that the canister never gets too cold while in use. If you do this you MUST monitor the canister temperature for safety of course, but that is rarely a problem.

However, if you have a static situation where the canister is at -30 C (eg left behind in an igloo for several days during a cold spell), then you might have a problem. Will Rietveld uses a propane stove for this very successfully.

Cheers

I've edited my summary to reflect responses from Douglas and Roger. Thanks

Hi Douglas

> although when it's that cold out I pack the canister in snow to keep it warm.
Now that is something which not many people will think to do! It needs 'warm' snow of course.

I have heard that even in very cold conditions the inside of an igloo can get up to 0 C when people are cooking inside. Will R has experienced this.

Cheers

Jim, a comment about your "#4" =For temps between -10C (+14F) and 0C (32F) you could use MSR IsoPro red canister fuel or Kovea white canister fuel (propane/iso-butane mixtures) with an upright canister.=
I have been at 2000 M on Mt. Rainier, 24*F, with a 1/2 full red MSR canister and it was barely pushing a flame. In 15 min it made my buddy's water was maybe luke warm and the stove flame was getting smaller. This is on the warmer end of the graph but still caused a problem.
We had a MSR Dragon fly as a back up so all was well.

I now use a Coleman Xtreme and a MSR Windpro with an inverted canister and have never had a problem

Edited by bestbuilder on 10/27/2010 16:39:39 MDT.

One morning last fall, the temp when I woke up was 18*F (-8*C). I hadn't put my MSR canister in my sleeping bag, and I knew I had to warm it up to make it work. I put it inside my coat for about 20 minutes (a somewhat frigid experience at the beginning!) and it worked just fine. However, I also found that I needed to prewarm my butane lighter. Once I got that warm (only about 3 minutes under my jacket), everything worked just fine. I had a piece of thin foam to insulate the canister from the ground, and used a ground-to-pot windscreen that went 3/4 of the way around the canister. This kept the canister from getting cold again while I was heating my water. I of course checked the warmth of the canister at frequent intervals. It stayed cool, but not cold, to the touch.

Frankly, most of the article was obscure to me, since it has been 60 years since my high school physics class. It's good to remind everyone that isobutane canisters need an extra boost of warmth to work in cold weather!

Articles like these are why a membership in BPL is worth it. BPL has to be the most informative backpacking website going when it comes to objective, science-based equipment testing.

Jim an y'all- thanks!

I didn't get that stuff either but I knew (well, hoped) I wasn't the only one. I love this place cause people aren't afraid to ask the gurus what the Hell their mosaic of charts means- AND they will gladly answer. (except when Sir Nisley gets the same question repeatedly) :)

I guess I'll just stick with the Spider and not look back

Well done and timely--- my last trip found me cooking breakfast below freezing and I wondered about stove performance in cold weather.

I wonder if a chemical toe warmer pack might help on a cold morning? They aren't terribly hot (safe on your toes) and might add just enough heat to a canister to safely get a breakfast going.

ive use them and they work fine for me ... better than the ole warm with a lighter trick ... lol

The application of a 3/4+ circle of reflectix around the stove/pot during use will warm the fuel canister, thus repressurizing it, and increasing the efficiency. The surface temp of the cannister can safely reach 120 degrees. With a 1" minimum gap of windscreen around the pot,the canister has plenty of ventilation room to not overheat. This process allows for full fuel usage, even at the very end of capacity. It shortens cooking time as well.

Cowboy

Jim - one small point:

"3. For temps above -25C (-13F) you can use any of the mixtures that contain both propane and iso-butane with a stove designed to burn canister fuel fed to it as liquid (connected to an inverted canister)."

For a liquid fuel stove, the iso-butane is not neccessary. It will work just as well with regular butane. What is required is 25% or more propane.

And a general point: all the temperatures in the article refer to the temperature of the CANISTER. This could be more (or less) than ambient!

Where can you buy Kovea fuel?

> Where can you buy Kovea fuel?
That's more difficult. Each shop makes its own buying decisions - often depending on what rep comes around.

CAUTION: if you see a cheap canister with a label saying "Primus, Compagnion, ????" (I forget the last name), DO NOT BUY IT! I tried it and found that the mixture is raw unfiltered gas with a lot of dust in it. My stove blocked up at once - several times. A cheap Chinese import I suspect.

Btw, that is NOT the same thing as the Primus Power Gas canister. The real Primus canisters are good.

Cheers

Hi all

Someone mentioned that they used to use plain butane canisters on Everest, back in the 'good old days'. Out of interest, I generated a canister pressure chart for the summit of Everest at -28 C (ambient pressure about 300 mBar).
.

.
Indeed, looking at the red curve we can see that it would JUST function at -28 C. That curve starts with 15% propane, but quickly falls to a nearly pure n-butane mix by about 50% remainder. So if the climber could get the canister any warmer than -28 C he would be cooking.

Cheers

In the article you mentioned the Coleman propane canister with a full weight of gas and canister at 935 g. I had look at Coleman's stoves for these canisters and they do look heavy... No weights on Colemans website (that I could find), but my guess is at least as heavy as your typical white gas stove. Given that my large MSR fuel bottle which full of white gas weighs in at around 875 g (220 g for the bottle w cap and fuel almost to fill line) why would I choose the propane stove?
It seems to me white gas would give me about the same total system weigth and more fuel as a bonus?

My Coleman remote propane canister stoves (3025-701 and 5452-700) weigh-in at ~19oz each. My Coleman Xtreme Powermax stove converted to straight propane weighs ~16.oz with storage bag and 2 adaptors.