MELTING SNOW: Fuel Efficiency and Boil Time Comparisons of Four Gas Backpacking Stoves in Winter Conditions

[Ryan Jordan]

I did some boil time/fuel efficiency tests this week on four stoves: MSR XGK II (2003), MSR Simmerlite (2004), Coleman Powermax Xtreme (2004), and Jetboil PCS (2004). I used the MSR windscreen and the 2L aluminum pot from Antigravity Gear for the liquid fuel stoves.

Conditions: 19 *F, 1-3 mph breeze, partly cloudy, nighttime (late evening), snow on ground.

Test goal: measure the time and fuel required for each stove to prepare 2L of boiled water, collecting data to help decision making for the SUL Winter Challenge.

Notes:

1. Time zero occured at the time the match was lit to the stove, and thus, the time measurements included priming time of the XGK and Simmerlite.

2. Boiling was observed when steam was pouring out of the pot, and verified visually by a wildly rolling boil.

3. All tests were started with 8 oz of 50*F water in the pot. Snow was added after the pot was placed on the primed stove.

4. For the three stove systems using the 2L pot (XGK, Simmerlite, Xtreme), the general process was as follows: light stove, start timer, let prime (not applicable to the Xtreme), put the pot on the stove, add enough snow for 1.5L of water, allow to come to a boil. Upon reaching a boil, decant 32 oz into a water bottle. Place pot back on stove, add enough snow for 1.0L of water, allow to come to a boil, stop clock.

5. For the Jetboil, the general process was as follows: light stove, start timer, add enough snow for 0.8L of water, allow to come to a boil. Upon reaching a boil, decant 24 oz into a water bottle (stove stays lit while doing so). Add enough snow for another 0.8L of water, allow to come to a boil. Upon reaching a boil, decant 24 oz into a water bottle (stove stays lit). Add enough snow for the final 16 oz. Let come to a boil, stop clock.

Results

Time to Boil 2L of Water from Snow

XGK: 20 minutes
Simmerlite: 21 minutes
Xtreme: 21 minutes
Jetboil: 54 minutes

Fuel Consumed

XGK: 2.8 oz
Simmerlite: 3.2 oz
Xtreme: 2.2 oz
Jetboil: 1.5 oz

** END **

[Tony Burnett]

Just trying to understand the snow melting process a bit…

How exactly is “add enough snow for 1.5L of water” done?

1) Leave lid off
2) add chunks of snow
3) wait for it to melt down a bit
4) Repeat 2-3 until water level is reached
5) cover
6) wait for boil

Back on topic:

Were the “systems” (fuel bottle, stove, fuel, etc.) at ambient temperature before starting?

[Ryan Jordan]

>> How exactly is “add enough snow for 1.5L of water” done?

Yes, Tony, basically that’s how it’s done. Usually step (5) cover is between steps 2 and 3, though. I usually only pull off the lid once during the addition process.

Were the system components at ambient at the start of the test? Yes.

[Zeno Martin]

This is great and exactly what I was looking for. It looks like the Coleman is clearly the winner in my opinion since it has close to the fastest time and uses less fuel and has the benefits of a gas cartridge (clean and no priming). For my purposes weight of stove is not critical. Thanks, great test!

[Joshua Mitchell]

so, even though it was cold the jetnoil still worked okay? (and was actually more effecient fuel-wise than the others?)

so it IS a viable method for melting snow…

[Ryan Jordan]

Yes, the Jetboil did fine. Slow, but a fuel miser, for sure.

What concerns me about the Jetboil (and any canister stove) is the preferential use of certain fractions of the gas, rendering remaining fuel less volatile. It would be interesting to run these tests until that big canister (the primus 450g is what I used) was empty, and see how performance changes as the fuel gets low.

[Joshua Mitchell]

Yeah, it would be interesting to see if it can still melt with less volatile fuel… I imagine that it will but it will take even longer.

[Mike Clelland]

This is great info!

I do a lot of winter camping, and I often think I should go thru this exercize, I am glad you did it for me!

Also – any info for an MSR WisperLight? I know it is pretty similar to the SimmerLight. But what is it???

thanks,
M!

[kevin davidson]

i had originally posted this on the Ryan Winter SUL thread but this seems relevant to this discussion.

With the 4 stove systems ( using the results and equipment of Ryan’s tests) — the Jetboil and the Simmerlite would be the clear winners from a weight standpoint if we were just boiling 2L of water (22 oz total system weight for the Jetboil and 23.1 Simmerlite– weights used inc. smallest Jetboil cart. and a Sigg fuel container w/ just enough fuel for the MSR stove to do the test). A stripped down Xtreme could be as low as 23.4 oz. using a small powermax cartridge, a stock extreme would be 27.4. The XGK would also be 27.4 oz. minimum.

But, the longer the trip/ more snow melting sessions, the Xtreme seems to leave the others behind.
Say for a total of 8 liters of water melted (4 seperate sessions), approx. weights would be–

stock Xtreme-27.4 oz.( same single cartridge used)
and a Xtreme given a diet would be as little as 23.4 oz.
Jetboil -29 oz. (2 cart.) or w/ 1 large MSR cart., 27.65 oz.
Simmerlite- 32.7 oz.
The XGK leads the rear once more–35.8 oz.

However–when we go to 16 Liters of water from snowmelt in 8 melting sessions— we find a different ranking.

Jetboil with superlarge Primus cartridge( as per Ryan’s figures)

---

= 38.2 oz.
stock Xtreme (w/ 1 lg. and 1 sm. cartridge)=41.0
modded Xtreme could go down to

---

37 oz
XGK

---

43.8 oz
Simmerlite

---

45.5 oz

I won’t editorialize, here. Multiple conclusions are possible.

[Anonymous]

I don’t see the point in doing these tests for boiling times. IMO, the testing should be timed to melting because that is all I am going to do as a lightweight hiker. I will melt snow and treat with chemicals in winter, for my cooking and my drinking water.

[Don Selesky]

The Coleman Expert (a slightly heavier version of the Extreme) has been my stove of choice for the past few winters backpacking in NH. It’s easy to light, efficient, and avoids the issue of spilled liquid fuel. With the addition of a MSR windscreen, it works great down below zero. It’s not the absolute smallest or lightest, but it is very reliable.

[Tony Burnett]

I’ve often wondered the same thing. You will most likely at least warm the water in an attempt to keep you warm (in your bag) or to prevent it from freezing (during the day in your pack). So, I wonder if that’s why folks boil? Since they are almost there anyway.

[paul johnson]

see post at 1033 in other thread for comments on boiling and fuel consumption. let me know what you think.

[Rick Dreher]

I’m curious as to who out there is chemically treating melted snow and where are you camping that you feel it’s necessary to do so?

I know there is a high prevalence of gastroenteritis at Denali and likely numerous other popular peaks, making treatment or boiling prudent, but I’ve never snowcamped anywhere where I found it necessary to do anything more than sieve out the pine needles.

[paul johnson]

Rick,

on a somewhat related note:

according to the CDC, 10min of rolling boil is recommended when using heat as a means of water purification. how many really “burn” the req’d fuel to acheive a 10min rolling boil?

i just happened to come across this extreme boil time while reading about Katrina. wasn’t explained as why so long. it was attributed to the CDC. might be overkill as even two minutes of a rolling boil (not a simmer) will kill even larger parasites. some spore formers won’t be totally eliminated even by five minutes of boiling. these, however, are not the type of bugs normally expeced to be in backcountry waters.

[Anonymous]

The few times I have snow camped even our leader chemically treated his water after melting it, so I do it as a precaution just as I do in three season camping.

I would also like to poll and see WHEN people do their melting/boiling? We have always done it once daily before the evening meal.

If I was in a post-hurricane situation I may well heed the CDC recommendation but not for camping. I would rather see what that northern national park was recommending to prevent the hydatid cyst infection.

[paul johnson]

>>”I would rather see what that northern national park was recommending to prevent the hydatid cyst infection.”

filtering is what was definitely recommended. perhaps boiling for 10min also – can’t remember.

chems & UV (at levels AquaStar and Steripen produce, it is ineffective for any reasonable exposure time).

[Anonymous]

http://www.nps.gov/isro/drinking.htm

Boil water for at least two minutes or filter through an adequate filter (0.4 microns for bacteria; 25 microns for tapeworm).

[Anonymous]

The few times I have snow camped even our leader chemically treated his water after melting it, so I do it as a precaution just as I do in three season camping.

I would also like to poll and see WHEN people do their melting/boiling? We have always done it once daily before the evening meal.

If I was in a post-hurricane situation I may well heed the CDC recommendation but not for camping. I would rather see what that northern national park was recommending to prevent the hydatid cyst infection.

[Tony Burnett]

I remember reading a trip report? Technique article? In which Dr. J mentioned melting snow twice per day? 2L am (to carry and drink during the day), and more in the evening. Any one find that article, I can’t.

Found it…Winter Water Routine

If you were to do all of it in the evening, you’d need more storage correct? Say 4-6L? Do most winter hikers only dring 2L during the day? How do you keep it from freezing while hiking?

[Tony Burnett]

Re-reading the above article, it seems as though Dr J melts snow 3 times per day…

Mid-day: 2.5L melt no boil!
Evening: 2.5L melt and *boil*
<optional 3am re-heat?>
Morning: re-boil (should be re-heat??) 1.5L for breakfast and then melt (and boil??) another 1.5 L.

Leave camp with 2.5L.

Repeat…

[Rick Dreher]

Let me refine my question a bit.

All I’ve ever observed in my snowmelt pot has been tree debris, pollen and the occasional frozen insect (nope, not claiming microscopic vision).

I only snowcamp in seasonal snow in western U.S. mountains. Whenever possible, I gather snow for drinking water in clearings, well away from trees to minimize windblown debris. My presumption regarding my “source” snow is that there’s little or no chance of it carrying disease pathogens–no viruses, bacteria, protozoa, etc. Further, visual inspection should alert me to the presence of animal or human waste in the immediate area where I’m collecting, making it relatively easy to avoid.

So, if I’m going to treat or filter my melt water, what am I targeting and how did it get there?

[Don Selesky]

I try to drink as much as I can before I take off in the morning carrying 2 liters. I go through the drink-as-much-as-I-can routine in the evening at camp. Don’t want to carry more than 2L, but I definitely can drink that much while hiking.

[William Siemens]

Thanks Ryan, good info. A question occurred to me…I have read somewhere, probably here on this forum or in the print magazine, that you can save fuel by running the stove at less than full-tilt-boogie. I realized that when its really blasting, a bazillion btu’s are floating up into the air…So am wondering, if you used the Xtreme at a moderate setting, not as much heat escaping arount the side of the pot, if maybe you’d end up with boil times and fuel economy more like the Jetboil? Inquiring minds want to know. Cheers, Bill

[paul johnson]

Rick,

you make a real good point here. good thinking. i still, not very often, mind you (i try, sometimes, to act like an adult) eat “virgin” snow.

there are no pathogens, TMK (to my knowledge), that i can think of that are found in “virgin” snow. how they would get into pure “virgin” snow, i can’t even imagine. if you’re at all concerned, dig down a ways and you’ll obviously find snow not exposed, except for while falling and a short time afterwards, to whatever else might be in the air – if anything (these aren’t the types of viruses, i.e. airborne pathogens, we’re normally concerned with anyways). this snow also has never been in contact with the ground or any living thing. also, not too many birds flyin’ about during a snow storm, right?!

[note: BTW, HTST (hi-temp, short time) pasteurization of milk is performed at ~162deg F for ~16-20sec. this is sufficient to kill bacterial and viral enteric pathogens – acc. to the FDA. also, all “bugs” in the milk get ~5log (IIRC), reduction fr/HTST pasteurization. this is a common method of pasteurization used by dairies. i only mention this to show that, for snow at least, boiling is not necessary to obtain pure drinking water.]

i gotta’ believe that it’s ‘ok’ to eat/drink this snow/water w/o purifying. why? kids all over the world would be comin’ down w/all manner of afflictions, diseases, and plagues. many of us would never have made it into adulthood with all of the snow we ate. i know, not a very scientific method, but w/so much anecdotal evidence to the contrary, how can we believe pure “virgin” snow can make one sick? just think of kids growing up for past several millenia as one giant field experiment in snow eating. our observation of the results of this experiment would be that kids can eat pure “virgin” snow w/impunity – and this snow isn’t even heated to make drinking water. i think we would be safe in extrapolating these observations to adults.

as a kid growing up in 50’s and early 60’s, the only popular concern (prob. a mother’s phobia) we heard was radioactive fallout from the “bomb” tests (in the NE, we live on the receiving end of the jet stream/prevailing winds).

oh…and…as mom always warned, “Don’t eat the yellow snow!!”.

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