Home › Forums › Campfire › Editor’s Roundtable › Lightweight Stove Systems for Group Cooking Part 3: Performance of Inverted Canister and White Gas Stoves For Boiling Water and Melting Snow at Subzero (F) Temperatures
Dec 31, 2013 at 3:10 pm #1311604
@maiaLocale: Rocky MountainsDec 31, 2013 at 5:00 pm #2059198
@rosyfinchLocale: the mountains
"White gas systems may not offer significant advantages in terms of fuel efficiency (fuel consumption per unit volume of water boiled), but may offer significant advantages as stove run time increases (as may be required for boiling large volumes, melting snow, or operating at subzero temperatures)."
White gas also had the advantage of dual use:
It can be used to start a wood fire. For instance, if the wood is a little wet and matches don't do the trick.
BillyDec 31, 2013 at 9:03 pm #2059228
@retiredjerryLocale: Oregon and Washington
Interesting data – inverted stoves work pretty good at very cold temps
I don't think white gas makes a good fire starter – it's dangerous because it flares up too much, and it burns off too quickly before wood starts burning. kerosene or wax or esbit or petroleum jelly are better. But, white gas can be used if you're careful.Dec 31, 2013 at 9:34 pm #2059230
@rosyfinchLocale: the mountains
White gas fire starter:
That's what we used to call "woosh"
Can't get the fire to start… add some "Woosh"
Of course you can always think of something better to take… when siting at home.
But you are out there using a white gas stove and you didn't think to bring fire starter, then, having some "woosh" is a very good think indeed!
BillyJan 1, 2014 at 7:04 am #2059257
@jamesdmarcoLocale: Finger Lakes
Well there are a couple things I would minorly quibble with.
While snow melting does include the phase change of the water, the actual temperature of the snow can have a reltivly large impact on the overall boiling time and fuel consumed.
Solids change temps with the ambient air, minus the ground heating/insulating effect.
Taking snow from the surface at -10f, for example may be significantly different from digging down several inches to the snow close to the ground. An example would be near streams or any water sources. Taking the snow from the top would give near ambient temps, but snow dug from near a spring may be significanlt warmer at 28F or so. Even if no actual water is available. For the same weight or volume, the 18F difference would be significant.
The overall heat density between typical canister gas and WG is roughly 5%. This accounts for a portion of the fuel consumption differences shown in the tables.
Minor quibbles, like I say, and a good article.Jan 1, 2014 at 5:23 pm #2059440
1. What type of canister fuel was used, butane propane mix or isobutane propane mix? Butane boils at about 0C while Isobutane boils at about -15C. Also what was the mix ration % butane verses % propane?
2. How often were the canisters used before a new canister was used? At very cold temperatures most of the pressure in the canister is from the propane. Some of the longer boil times could be the result of propane depletion in the can. With less propane pressure you will get a smaller flame even if the stove is always used at full. I assume you were always using the stove at full but I didn't see that mentioned.
3. What was the size of the canister used?
4. Under what altitude and wind conditions were these measurements made? Was a wind screen used?
Basically I would like to know how much variability you got for a give condition. If you ran it 5 times at the same temperature, what was the variation in the boil times. If there is a lot of variation the conclusions may not be accurate.Jan 21, 2014 at 3:46 pm #2064947
Ryan: Do you suppose certain inverted canister stoves may perform better at subzero temps than others? In other words, is it possible to test different inverted canister stoves in subzero conditions before we relegate the champ to the white gas stove?
I guess I ask this question out of recent experience I had in Colorado during their record breaking season cold. While camped in the Indian Peaks Wilderness at somewhere in the range of -10 to -15 degrees F, we ran a Primus Spider Express and a Kovea Spider inverted side by side. While I own both stoves and they perform very similarly in above zero conditions (experience, not tests), they clearly did not perform equally in subzero temps. The Primus acted like it was sitting in my kitchen at home, able to melt Kryptonite while the Kovea flame quality diminished rapidly. I did swap canisters between the two stoves, if someone were to wonder.
I fully realize there could be other factors at play here, such as stove malfunction (but the Kovea did run fine once returned home to more rational temps) and other issues I may not be aware of. I also realize you science guys may take my lunch and shovel me some bologna, but oh well, I guess if a guy sees a UFO, then he is a believer.
I appreciate your work on this subject and enjoyed the read.Jan 21, 2014 at 4:08 pm #2064954
@rcaffinLocale: Wollemi & Kosciusko NPs, Europe
For me, the first real message of all this is that trying to use a single stove for either 2.9 L or 4 L of water for a whole group may be asking a bit much of the poor stove. I find a 1.5 L pot over an inverted canister stove (or a white gas or kero) works just fine for 2 people, with quite reasonable melt and boil times.
Ryan's comment about needing a whole lot of extra clothing if you are going to obey the MSR lawyers and sit outside in the dark in the snow while cooking is also very much the second point. MSR are just trying to avoid any liability at all with these strictures. It's an utterly stupid idea. We get inside our double wall tent, Sue gets right into her SB or quilt, and I get half into mine. Then with the outer door half open I fire up the stove. The inside of the tent quickly gets much warmer than outside, the stove runs just fine, and all is well. I did say the door is half-open: quite enough ventilation for a good low-CO stove. Not sure I would want to try it with a Reactor though: too much CO for my liking.
The third vital point mentioned is to consider where you get your snow. On the surface it will indeed be very cold. Deep down near the ground it is much warmer. So many people seem to think that all snow is around freezing point: it sure isn't. In fact, I will happily spend a quarter of an hour digging down to water. It's worth it.
CheersJan 21, 2014 at 5:43 pm #2064976
@b-g-2-2Locale: Silicon Valley
There is an additional winter trick to add to Roger's routine.
Before you ever crawl into the tent, you go collect your clean snow into a clean plastic garbage bag. The amount varies with how many people are cooking. You wedge the full bag into a vestibule or into the air space between the inner and outer tent, and the top of the snow bag must be reachable from the tent inner door. Typically you have your stove in the vestibule where the ventilation is. Then, as your snow melt pot works, you can stick your cup into the snow bag and dump it into the melt pot. This keeps you from having to run outside to fetch more snow. You can probably do this by only half-unzipping the inner door. If the cold wind is blowing, the snow bag can represent an extra piece of wind wall. Even if heat in the tent melts some of the snow, it will just re-freeze in the bag, and therefore it will be even easier to drop in the pot.
Brought to you from the school of Been There, Done That, Saw the Movie, Read the Book.
–B.G.–Jan 22, 2014 at 1:33 am #2065045
@rcaffinLocale: Wollemi & Kosciusko NPs, Europe
Good one there. I usually just dump a heap of snow by the side of the vestibule (like against it) and hack at it with a cup from underneath the edge of the vestibule, but a light plastic bag could be useful.
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