Lightweight Stove Systems for Group Cooking Part 1: Basic Framework for Selecting A Cooking Pot and Predicting Fuel Needs

[Roger Caffin]

Hi Aleksi

Then the article proceeds to report empty canister total weights for a three-person cook group in the range of 0.77 kg – 1.08 kg.
I suggest you recheck those figures. They might be right for the heavy LPG steel 1kg bottles – maybe, but the canisters we use are about 130 – 140 g for a 220 g canister. The lovely Powermax canisters are even lighter.

Cheers

[Aleksi K]

Yes, the figures might be too high, but still: if you need to carry 0.5 – 1 kg of empty canisters, how a 383 g liquid fuel stove can be “all but obsolete in our community”? People don’t go on longer winter hikes?

 

[Roger Caffin]

if you need to carry 0.5 – 1 kg of empty canisters

Where or how do you get this figure?
Either you have misread something, or every canister user here has really got his scales wrong.

Walking for 2 months across the Pyrenees with my wife in alpine conditions, I was carrying one 450 g gas canister for a fortnight for the two of us. That was maybe 160 g empty – I forget the exact figure. When the canister got low I bought another one in a small town. When the canister got empty I punctured it and dropped it off at any little shop – having first shown them the hole.

So your figures make zero sense.

Cheers

[Aleksi K]

Those figures are from Table 7. Comparison of System Weights For a 7-Day Expedition With a 3 Person Cook Group.

Your Pyrenees hike was probably a different type of winter hike? Not melting all water and cooking all food for 2 persons and 2 weeks with less than 450 g of gas?

My point is: liquid fuel has close to zero relative container weight in larger quantities, so liquid fuel stove systems are more lightweight when usage is high enough. They also have faster boil times at low temperatures, which is also an important advantage. That was the topic of part 3 of the article series. So I don’t see how liquid fuel stoves would be completely obsolete?

 

[Roger Caffin]

Summer: we use 30 g of gas per day for 2 people. That I can personally state.
Winter: I allow 60 g per day for 2 people, and that includes some snow melting.
Container weight for white gas – arguable. I did not write that article. The figures given may be out of date by now.

They also have faster boil times at low temperatures,
They don’t. That is a myth we have debunked ages ago. White gas stoves generally peak around 2.8 kW; canister stoves peak around 3.0 kW. A canister stove has more power available than a kitchen hot plate.

Safety: whoo hoo! I suspect a large fraction of white gas users will admit to at least one exciting episode. Tents have been burnt down, people have been burnt. Starting an XGK involves a football-sized fireball – according to the MSR instructions. Meanwhile, thousands of canister users safely light their stoves inside their tents and cook happily. In howling snow storms.

For the record: I have used kero, white gas, canister, alcohol and Esbit stoves, fairly extensively.

Cheers

[Aleksi K]

With such low consumption figures, canister stoves are a clearly the best option. I guess you are not melting that much snow or then your stove system is insanely efficient?

Canister stoves are way safer and nicer, which is why I also use them for everything else except week-long winter hikes. Though using ethanol for pre-heating the liquid fuel stove makes starting it cleaner and safer.

[Roger Caffin]

It’s not the stove itself which is so efficient, it’s how we use them. A good windshield, a lid on the pot, not running too high – such things can just about double the effective efficiency. Cooking inside the tent vestibule gets you out of most of the wind as well.

Also, with canister stoves, we can turn them off as soon as they are not needed, whereas white gas stoves are usually left running due to priming hassles.

Cheers

[James Marco]

Aleksi, there is a world of differences between WG (liquid fuel) stoves. Some compare vary favorably with canisters. For example, my older SVEA consistently gave me the same usage numbers as an MSR Pocket Rocket…9-12gm/L or about 11-14L per full tank. Some high efficiency tricks do not work all that well, though. The lowest setting it goes to is about the same as a normal alky stove. But, you cannot fully enclose it against wind…it overheats after about 10min of operation. Anyway, the actual fuel BTU or Kw/H is only about 7% or so less (from memory.) So, I would expect a slightly higher consumption. My canister stove gets about 8-10gm/L.

The kicker is the can. The weight of the can can kill overall fuel efficiency pretty fast. In every case, I can carry the extra 7% of WG fuel easily rather than pay for the weight of the can. About 90% of the weight of canister fuel is taken up by the can, soo, really, it is only slightly more efficient than carrying an alky stove and using ethanol. With larger cans, it gets more efficient, but, it still looses out to carrying liquid fuel in plastic bottles. This is ONLY the fuel.

Now for the big “BUT.” WG stoves are almost always heavier than alky or canister stoves. It takes a LONG time for the cans to override this.

[Aleksi K]

Thanks for the interesting points! I have never really explored this area, as using a canister stove for something like a two-day trip is a no-brainer and all our longer trips involve other activities with their gear, which implies a heavy mode of travel with pulkas and a basecamp tent. Guess I’ll be needing yet another canister stove to explore the middle-ground…

[Roger Caffin]

About 90% of the weight of canister fuel is taken up by the can,
Well, not really.
MSR ISO-PRO screw-thread: 132 g (can) + 227 g (fuel): 63% fuel
Primus Powergas (red): 153 g (can) + 230 g (fuel) : 60% fuel
Snow Peak 230: 147 g (can) + 230 g (fuel) : 61% fuel
Coleman Powermax 300: 86 g (can) + 300 g (fuel) : 77% fuel
Primus 2202 (white) : 230 g (can) + 450 g (fuel) : 66% fuel

Cheers

[Ben Pearre]

I’d love to see this article finished. Or better, updated. All those TBD rows are tantalising! I especially want to see some trials of heat-exchanger systems (more relevant as it’s so easy to buy small heat-exchanger pots now, both as parts of system stoves and stand-alone ones). And hear more about how to run inverted-canister stoves below -10—just drop the canister into a water bath, as I do with my JetBoil?

[Roger Caffin]

@Ben: BPL has a LOT of articles on canister stoves, and they will answer most of your questions directly. Yeah, I wrote many of them.

how to run inverted-canister stoves below -10—just drop the canister into a water bath,
The typical 30% propane / 70% butane canister is good to about -24 C without any assistance. With a bit of radiation from the stove, you can push an inverted canister stove way below that. Yes, a bowl of water would work, although at -10 (C/F) I suspect it might freeze up fairly quickly.

When washing up in the winter in the snow my wife has to dry the bowls very quickly after I have washed them. Failing that, I give the bowls a bit of a whack and the ice falls off. Whatever works.

Cheers

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