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 **

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?

>> 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.

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!

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...

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.

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.

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!

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.

Edited by kdesign on 11/16/2005 09:53:37 MST.

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.

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.

Edited by backslacker on 11/16/2005 17:43:10 MST.

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.

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

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.

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.

Edited by pj on 11/23/2005 17:36:04 MST.

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.

>>"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).

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).

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.

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?

Edited by tlbj6142 on 11/16/2005 15:06:36 MST.

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...

Edited by tlbj6142 on 11/16/2005 16:02:11 MST.

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?

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.

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

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). [i ate a lot of snow - guess that explains quite a few things...!!!]

oh...and...as mom always warned, "Don't eat the yellow snow!!".

Edited by pj on 11/17/2005 02:48:03 MST.

On the PCT through the Sierras there is a red fungus? that grows on the snow. I know PCT hikers have gotten sick from it and I saw it myself on my JMT hike this past summer. Anyone know what that is?

>red fungus? that grows on the snow.


You can Google a lot of decent info on this topic. Here's one quick reference: <http://www.straightdope.com/mailbag/mpinksnow.html>

Interesting that it's UV resistant, so my Aquastar probably wouldn't be the best solution for purifying watermelon-snow meltwater.

good info. many thanks. was thinking that it might have been an algae (snow/water + red color), but couldn't imagine how it would get there and wasn't at all sure enough to venture anything but a mental guess. go figure.

>>"Interesting that it's UV resistant, so my Aquastar probably wouldn't be the best solution for purifying watermelon-snow meltwater."

perhaps more research needs to be done. remember the UV range of the EM spectrum is divided into 3 sub-ranges, viz. UV-A, UV-B, and UV-C. both Steripen and AquaStar produce UV-C light primarily at the 254nm wavelength. also, recall that the UV-C range is the most bio-active portion of the UV range(s).

i didn't look at all of the links, but one of them speaks of UV resistance. however, the range of wavelengths cited are UV-A and UV-B. these have less of an effect than UV-C. i also don't know the level/intensity of UV-C the algae is exposed to in the Artic and on Mtns, and how this level compares to SteriPen and AquaStar levels/intensity.

i'm not saying UV-C would work, just that it may work better than UV-A and UV-B. the link had no info on UV-C. so, we are left wondering.

BTW, the cells are large enough that even a so-called "cyst" filter will remove them.

so, now our mother's should also tell us "Don't eat the pink/red snow either".


EDIT:
be sure to read Rick's later post. in it he mentions a toxin, hence filtering or any method that doesn't deal with chemicals is not a viable method. bottom line: stay away from colored snow.

Edited by pj on 11/17/2005 14:26:50 MST.

I typically see pink snow in summertime conditions when there's usually plenty of water available directly and it can be entirely avoided. Not to say that the algae can't appear in meltwater!

On the topic, I do know folks who've ingested some of the stuff and report it gives them the runs, but nothing more dramatic. I've never seen it described as an acute health hazard.

Donning my speculation hat, the algae likely manufactures a toxin--in the manner of the famous red tide algae but not nearly as toxic. Killing the algae is probably not the goal; rather, you'd want to neutralize or remove the toxin. Perhaps carbon adsorbtion?

Best to avoid in the first place!

p.s. UV will kill algae, I've got a UV system on my koi pond to do just that.

Edited by halfturbo on 11/17/2005 14:01:40 MST.

I belive the Steri Pen water purifier uses UV light to kill bacteria

Rick,

regarding your pond's UV system, do you know the wavelength and intensity/power level of the light produced?

Hi Paul,

My pond system emitter is 25 watts and has an output range of 250-280nm. The maker doesn't give an intensity spec, but does note it's 40% efficient in generating UV (I suppose the rest goes into visible light and heat).

These units are available in many wattages and sizes to match pond size and conditions.

FWIW the UV AquaStar has a target output 254nm at 4 watts.

The Coleman is great for ease of use, no priming, but at 19F below, the flame was so low it looked like a low fuel burn. The MSRs workred like blow tourches. Glad my companions had those.

Frank;

At -19F? Or below 19F?

> 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?

Yep. Moderate power, windshield, lid: I quite literally halved my fuel consumption.

> The Coleman is great for ease of use, no priming, but at 19F below, the flame was so low it looked like a low fuel burn. The MSRs workred like blow tourches. Glad my companions had those.

Well, -19 F is a shade cool...
But no problem: just move the Powermax cartridge around so it gets a bit of radiation from the stove to warm it up. And insulate it from the snow of course.
As long as you can touch the cartridge (pain thereshold about 40 C) it is NOT too warm.

Dr. Caffin,

good suggestion on the radiant heating of the insulated cartridge. also, "full-tilt-boogie" (good one!), now i know what the "f-t-b" indication on my stove dial means.

"pain threshold" at 40C? that's only 104F, and the cartridge is dry, not wet. "40C", a 'typo' right?

maybe the ans. is still pain threshold, but the 40C is a typo?

Edited by pj on 11/24/2005 01:56:37 MST.

The CDC recommends one minute of boiling, not ten, so far as I can determine. I will use two minutes if I feel the source has a high likelihood of contaminants. However, I'm careful about where I gather snow, and generally only melt it.

On an ancillary point drawn from this thread, what modding for weight loss is possible for a Coleman Xtreme?

Ted Ripley-Duggan

Ted Asked:
"On an ancillary point drawn from this thread, what modding for weight loss is possible for a Coleman Xtreme?"

Ted I don't understand the word "modding". Can you explain please.

Modding = Modifying

Great information from all. I have tried most of the stoves mentioned and have decided the Coleman Xtreme is my stove of choice for winter hiking. This past weekend temp's ranged down to 11F and had no problems at all with the stove. I have used it in below 0F as well with the same results. Aside from a somewhat tricky canister insertion into the stove, the problems are almost non-existent compared to my buddy's white gas models mentioned here. He gave up on the Dragonfly and now uses his whisperlite/shaker jet model. Few problems for sure but not as easy to use as the Xtreme. - John

Edited by JohnMacri on 11/30/2005 08:05:56 MST.

OK, I find myself with a question. Canister stoves are notoriously flakey in the winter. At least they are for me even in temperatures above 0°F with moderate winds. I can recall trips where a canister stove just plain did not work and the conditions were reletively warm and winds nearly nil.

So, what is it about the Coleman Xtreme and/or MSR Wind Pro stoves both of which use fuel canisters that enables them to work (or so it seems to be claimed) reliably at temperatures aroun 0°F (and perhaps below)?

On a strictly stock wieght comparison why should I not obivously go with the Wind Pro overr the Coleman Xtreme every time (no, I'm not going to modify an Xtreme or Wind Pro; I doubt I have the mechanical knowhow, let alone tools, to do it)?

** Ken **

In a word, liquid propane...

The Xtreme, by design, uses canisters that have a tube in them that draws up the liquid propane. Propane boils off well below 0F (-44F comes to mind???). This allows the stove to work at sub freezing temps.

The wind pro is "just as bad" as any other canister stove in the cold, **UNLESS** you flip the canister over which allows the liquid propane to leave the canister "first". Thereby behaving, more or less, like the native functionality of the Xtreme.

Edited by tlbj6142 on 12/15/2005 07:42:40 MST.

If the wind pro does work that way when the canister is upside down, aren't you going to get less use of a windpro canister once the liquid propane is used up?

Actually, it's because these stoves are able to take up liquid butane, not propane. Butane has a boiling point of more or less 32°F. In normal canister stoves vaporisation takes place inside the canister and once temperatures drop beneath 32°F, the vaporisation of butane slows down very fast (vaporisation of propane continues as long as temperatures are above -40°F).

In the Xtreme and in the Windpro in upside down mode, vaporisation of the liquid fuel takes only place in the preheaeter tube running over the burner head.

Edited by Woubeir on 12/15/2005 08:05:03 MST.

Hi Ken and John-

I'd like to add a little to Tony and Tom's excellent replies:

A liquid feed canister system (home-brew upside-down, or Coleman Powermax) has two cold-weather advantages over regular canisters. But first, some background.

Current generation canisters contain a mix of Propane and Isobutane, (plus sometimes regular Butane.) The problem with regular butane is that it boils at -0.5 degrees C. So if the ambient temp is below freezing, your fuel would not vaporize. Isobutane is better in that it has a boiling point of -11.7 degrees C. (Propane boils at -42.1 degrees C.) So, why not just use Propane in the canisters?? Well, Propane has a higher vapor pressure, so requires a stronger (heavier!) can -- like the giant cans used for car camping, or your backyard BBQ. So, in order to keep the small canisters light, yet still work at low temperatures, manufactures use the Propane/Iso blend.

This blend approach is not completely trouble free, though. The different gases in the canister boil off at different rates. So, as you run the stove, the Propane is used up first -- leaving behind the (iso)butane. This explains why partially used canisters are particularly bad in cold weather -- there is little propane left in them.

To make things worse, the fuel in a regular canister vaporizes inside the canister as the stove is run. This causes evaporative cooling of the fuel, lowering it's temperature. So even if you start off with a warm canister, after running it for several minutes, it will cool and it's output will drop off or stop. That's why canisters are problematic for things like snow melting where 30-40 minute boils are needed.

Ok, so what about the liquid feed canisters:

1) Since the fuel evaporation occurs outside the canister in a preheat tube prior to cumbustion in the stove, canister cooling is minimized during prolonged usage. This allows them to provide consistant output over long burn times.

2) The liquid fuel bled from the canister always contains close to the original mix of propane/butane. Because the fuel does not evaporate in the canister, the propane doesn't get used up first. This makes liquid feed canisters perform more consistantly over the life of the canister.

[If you just invert a regular canister to get liquid feed, the final 10g or so of fuel won't come out in liquid form and operation reverts more or less to regular gas-feed operation for the last few minutes of fuel use.]

Cheers,

-Mike

Edited by MikeMartin on 12/15/2005 12:01:53 MST.