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Tuesday, November 25, 2014

MSR Windburner – Wind Testing

What is the big advantage that the Windburner claims over other stoves?  Well, wind proofness.  I mean, if the Windburner can't handle wind, then why would you buy one, right?  Either the Windburner does well in wind or there isn't an overriding reason to buy one.

I thought I'd put it to the test.
Wind swept Snow Creek Canyon near San Gorgonio Pass, the perfect spot for wind testing.
UPDATE 26 Nov 2014:  I've added a table of comparative weights and prices among the current Jetboil and MSR 1.0 liter (or less) capacity integrated canister stove offerings.  See Appendix II.
I've also added a more in depth discussion of how many boils you'd lose out on using a Jetboil vs. a Windburner.  See Appendix I.  There's also a discussion of when and why fuel efficiency matters in the main body of the post.

UPDATE 27 Nov 2014:  I've added some videos in Appendix III that show the lighting of the stove in windy conditions.  Definitely more difficult than in still air, but doable.  I had far more trouble lighting the Jetboil even though the Jetboil has a built in lighter.

I tried a series of four types of tests:
  • Still Air
  • Light wind
  • Moderate wind
  • Heavy wind
  • Testing the MSR Windburner near San Gorgonio Pass.  Note that you cannot actually see the flame, only an orange glow.
    The enclosed burner of the Windburner is the secret to its windproof success.
A summary of my test results by test type is below.  The basic result of the testing was that the Windburner handled wind better, sometimes dramatically, than a Jetboil Sol.  See the comparative videos, below.

Test Results by Type
Still Air.  In still or nearly still air, the Jetboil Sol was clearly faster than the Windburner, sometimes by as much as 30 seconds faster.

Light wind.  In light wind, the Jetboil was still faster, but by a narrower margin.  The Jetboil's fuel usage went up slightly.  The Windburner's fuel consumption did not noticeably change.

Moderate wind.  In moderate wind, the Jetboil and the Windburner were more equal in terms of time to boil, but the Windburner typically would boil first.  The Jetboil's fuel consumption went up even more.  The Windburner's fuel consumption went up slightly but the change was small.

Heavy wind.  Here's where I was shocked.  I expected that the Jetboil would be markedly slower than the Windburner, but instead the Jetboil would not boil at all.  In heavier winds, the Jetboil would just blow out, and I never got the water to boil.  On the other hand, the wind had no discernible effect on the effectiveness of the Windburner.  Let me repeat that:  No discernible effect.  Needless to say, I was impressed.  I discontinued the comparison tests since I could get no meaningful boil times or fuel consumption figures from the Jetboil.

The day I did my testing , there were 35 mph/56 kph gusts predicted by the US National Weather Service.  Below are two videos, showing how the two stoves did.

Jetboil Sol in heavy winds.


MSR Windburner in heavy winds.


Now, of course you're not always going to be out in such dramatic conditions.  But no matter what, you're always losing heat with a Jetboil.  It's just a matter of degree.  Yes, you can shield it some, but you'll always be wasting some fuel just because of the burner's open design.  The Windburner is fundamentally more windproof.  The Windburner is fundamentally more fuel efficient in wind.

I'll put some numbers below in Appendix I that try to estimate just how much you'd be giving up using a Jetboil vs. a Windburner in terms of number of boils lost.
Wind farms dot the slopes above San Gorgonio Pass

Wind Resistance – Does It Matter?
Well, it depends.  If you're a low altitude backpacker, you probably can shelter your stove behind a log or rock, and wind resistance will matter less.  Note that I say, "less," not, "it won't matter at all".  You're always going to be saving fuel with a Windburner even in still air.  See also the next section on fuel efficiency.  I do note however that a Jetboil Flash has an MSRP of $100 USD whereas an MSR Windburner has an MSRP of $130.  If all you do is low elevation trips and you avoid high winds, the Jetboil Flash might be a good choice.  There is also a Jetboil Zip available for an MSRP of $80 USD.  The Zip is only 0.8 L (whereas the Windburner and the Flash are 1.0 L each), so it's not completely comparable to the Windburner, but it's worth mentioning.  See also Appendix II which contains a comparative table of weights and prices.

Now if you're an alpinist/mountaineer, a "big wall" climber, a backpacker given to spending the night at high elevation, or anyone who may find a sheltered spot difficult to come by, wind resistance might mean the difference between a nice hot meal – and eating uncooked freeze dried food, straight out of the bag.  If you rely on your stove for snow melting, you could wind up a whole lot worse.  If you can't get drinking water, you greatly increase your chance of getting hypothermia, and hypothermia leads quickly to death.  Hypothermia is simply not worth risking, period.

In high winds, even behind a rock or log, it's difficult to truly shelter a stove.  Anyone potentially facing high winds would be well advised to pick a Windburner over a Jetboil.

There's another way that windproofness matters – predictability.  Got fuel?  Are you sure you've planned your week long trip correctly?  I mean you don't want to be eating uncooked freeze dried food at the end of the trip just because you didn't bring enough fuel, right?  Well, hopefully, you've planned with a margin for error, but if you run into inclement weather, particularly high winds, your fuel estimates may be way off.  The Windburner is almost unaffected by wind.  You can make fuel estimates well in advance and rely on them.  With the Windburner, fluctuations in weather will not have you eating cold meals on your last couple of days out on the trail.
Commercial wind turbines in the San Gorgonio Pass area

Fuel Efficiency – Does It Matter?
Well, it depends.  If you're only going out for a few days, no high winds are predicted, and you always bring a fresh canister, then perhaps not.  While I like getting as much as I can out of my canisters, for a short trip with a fresh canister, it's not going to make much difference whether you use a Jetboil or a Windburner in terms of fuel used.  Only if high winds are predicted would I get worried about which stove would be the right one to bring.

Well, then, when does it matter?  When you have to bring an extra canister (or move up to a bigger canister).  An extra canister, even the smallest size, weighs about 7.4 oz/211 g.  That's nearly ½ pound.  In terms of saving weight, always avoid taking an extra canister or moving up to the next sized canister.  Look at the chart in Appendix I on how many boils you'd be giving up by using a Jetboil.  If losing those boils forces you to carry another canister (or carry a bigger canister), then it would probably be lighter overall to carry a Windburner (see examples, below).  Efficiency alone usually will not make up the difference for a heavier stove.  Only when you can avoid stepping up to the next sized canister or bringing an additional canister can a more efficient stove save you weight.

Efficiency vs. Weight – Examples
1. You normally will not save weight by being more fuel efficient alone. You just can't save enough weight that way to make up for a heavier stove. For example an aluminum Jetboil Sol weighs about 11 oz and the MSR Windburner weighs about 15 oz, a 4 oz difference. Now say that you save 1 g of fuel per 500 ml boiled, you boil twice a day, and you take a week long trip. Saving 1g twice per day for seven days is 14g.  In other words, you would need 14 g less fuel with the more efficient set up. 14 g is about 1/2 oz. Recall that in this example, the more efficient set up is 4 oz heavier.  Saving 1/2 oz in fuel will never make up for a stove that is 4 oz heavier.

2. You will save weight if you can avoid carrying the next largest size canister or carrying a second canister. The difference in gross weight between a 110g canister and a 225g canister is roughly 6 oz (4 oz of fuel + ~2 oz of steel container). If your 4 oz heavier stove is efficient enough to prevent you from having to carry a larger canister you've just saved 6 oz - 4 oz = 2 oz. Generally this type of weight savings will occur on trips of 7 to 10 days. The Jetboil Sol retails for $120. The Windburner retails for $130. Would I spend $10 to save 2 oz?  Well considering how many people there are willing to pay $150 for the titanium version of the Jetboil Sol which is only 1 oz lighter than the aluminum version (if you do a real comparison, not the spin doctored comparison on Jetboil's website), I'd say that a lot of people in fact would spend $10 more for the more efficient stove.

So there's my take on the wind resistance of the Windburner.

I thank you for joining me,

HJ

MSR Windburner Posts

Disclosures
The item reviewed here was provided to me at no charge for the purposes of this review.  I am under no obligation to review this or any other item.  I am not compensated for my reviews in any fashion other than in some cases I am permitted to keep the item reviewed.  Given that I have well over a 100 backpacking stoves, a free stove frankly isn't going to buy anyone a good review.  Stove companies must measure up if they want a decent review here.  I am an amatuer stove blogger; I make my living elsewhere, in the IT field.  I fit blogging in as time permits.  Inasmuch as my income is derived elsewhere, monetary issues do not influence the reviews on this blog.  Yes, I do have advertisements on the blog.  I typically derive about $1.00 USD per day from the advertisements (last I checked).  This is a mere pittance and does not influence my reviews in the slightest.  Revenue from the advertisements goes toward hosting fees, stove fuel, and the like.  The blog is self supporting in that sense, and my wife is quite happy that I'm not using the family's income to run the blog, particularly given how tough the economy is these days.
Appendix I – Boils Lost with a Jetboil (vs. a Windburner)

OK, so if you use a Jetboil instead of a Windburner, how many boils are you losing out on?  In other words, how many additional boils can you get out of a Windburner than a Jetboil for the same amount of gas?

Let's try to put some numbers to it.  Assume, for example, that you get a difference of 1 gram of fuel per 500 ml boil and that you boil water twice a day.  Over a week long trip, the Jetboil would require 14g more fuel than a Windburner.  An integrated canister stove can normally boil 500 ml with something around 6g of fuel.  Thus, if over a week you use 14g more with a Jetboil, then you'd be "losing" a bit more than two boils as compared to a Windburner.

I've mapped out a chart below, showing how much more fuel a Jetboil would use depending on how much difference there is in terms of fuel consumption per 500 ml boil.
Difference per boil (grams) 0.25 0.50 0.75 1.00 1.25 1.50 1.75 2.00 2.25 2.50 2.75 3.00 3.25 3.50 3.75 4.00
Boils per day (500 ml each) 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
# of days 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7 7
Total difference (grams) 3.5 7.0 10.5 14.0 17.5 21.0 24.5 28.0 31.5 35.0 38.5 42.0 45.5 49.0 52.5 56.0
Fuel grams per boil 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6
Boils "lost"  1 1 2 2 3 4 4 5 5 6 6 7 8 8 9 9

So, how much difference per boil can I expect?  My numbers should not be considered exhaustive, but in still air, the Jetboil required something on the order of 0.25 to 0.5 g more fuel per boil.  In light winds, the Jetboil required something on the order 0.5  to 0.75 g more fuel per boil.  In moderate winds, the Jetboil's fuel consumption rose considerably, requiring about 1.0 to 1.25 g more per boil; I noticed in particular that gusts really affected the Jetboil's flame.  I don't have an estimate for heavy winds because the Jetboil would not bring water to a boil.  Clearly though, the stronger the winds, the more fuel the Windburner will save as compared to a Jetboil.

Now, do my figures make sense for you?  Perhaps.  Perhaps not.  Maybe you boil more water per boil.  Maybe you boil more often per day.  Maybe you're taking a shorter trip.  If you'd like a copy of my Excel spreadsheet so you can try your own numbers, you're welcome to it.  Just write me at Hikin [dot] Jim [at] gmail [dot] com and ask me for one.  Please be specific as to what you're asking for; I get a lot of requests.

Disclaimer:  My numbers should not be considered authoritative.  These are ballpark estimates only.  The only way to get exhaustive numbers would be to take multiple Jetboils and multiple Windburners, burn through multiple canisters per stove in carefully controlled conditions, and average the numbers after all tests were complete.  I simply have not got the resources to do such testing, and I fully acknowledge that fact.
Wind turbines, San Gorgonio Pass

Appendix II – Comparative Table of Weights and Prices
Integrated Canister Stove  Capacity (liters) Weight (g) Weight (oz) Retail Price
Jetboil Sol (Ti) 0.8 279 9.8 $150.00
Jetboil Sol (Al) 0.8 312 11.0 $120.00
Jetboil Zip  0.8 345 12.2 $80.00
Jetboil Flash 1.0 400 14.1 $100.00
Jetboil MiniMo 1.0 415 14.6 $130.00
MSR Reactor  1.0 417 14.7 $190.00
MSR Windburner 1.0 432 15.2 $130.00

Weights are generally the manufacturer's stated weights in grams.  The notable exception is the weight of the titanium version of the Jetboil Sol.  The Jetboil website has "spin doctored" the numbers to make the titanium version appear lighter.  My number is based on an "apples to apples" comparison.   The weight of individual stoves will vary.  Ounces are a calculated figure based on a conversion factor of 28.3495.  Stoves are sorted in order of weight with the lightest stove first.  Note that all of the 1.0 L capacity stoves are within about an ounce of each other in terms of weight.  The spread is 32 grams from the lightest 1.0 L stove to the heaviest.

UPDATE, 7 January 2015:  I've received a note from MSR stating that production units are coming in heavier than the prototype units that the weights were originally calculated from.  MSR gave me a range.  Basically the unit I received is about in the middle of that range.  A weight just over 16 ounces should be about the weight of a unit that you would receive should you purchase one.  I might add that MSR was a bit chagrined about the miscalculation of the weights since they try to be transparent about such things.  I don't yet have an exact number for the revised stated weight, but it should be about 460 grams/16.2 ounces.  A bit disappointing actually.

Note:  My information is that Jetboil is discontinuing their Sol line of stoves (both types).
Size comparisons.
L to R:  MSR Reactor (1.0 L), MSR Windburner (1.0 L), Original Jetboil PCS (1.0 L), Jetboil Al Sol (0.8 L).

Appendix III  – Lighting the Stove in Windy Conditions
I've gotten a lot of questions about how easy (or not) the Windburner is to light in windy conditions.  Here are two videos of me lighting the stove with a fire steel in the same spot as the videos in the main part off this post were made.  These two videos were shot just before the other videos. It was definitely more difficult to light than in still air, but I had no trouble lighting the stove or keeping it lit long enough to get the pot on.  In still air, I can light the stove typically on the first strike.  In windy conditions, I found that it might take several strikes.  The type of fire steel that you're using may affect your results.  In these videos, I am using a Scout firesteel from Light My Fire.




6 comments:

  1. Wow...that's really impressive. I'm definitely leaning towards the windboiler when my rei dividend comes out.

    ReplyDelete
    Replies
    1. Hi, Miles,

      I was quite surprised at just HOW good the Windboiler handles wind. It's all but unaffected.

      HJ

      Delete
  2. Hey Jim, since you have both, can you tell me if the minimo lid will snap onto a titan kettle.

    ReplyDelete
    Replies
    1. Eddie, I don't have a MiniMo. You'll see some photos with a MiniMo in them, but it was borrowed. Sorry.

      HJ

      Delete
  3. The best review i've read on this stove. Keep up the excellent work.

    ReplyDelete
    Replies
    1. Thanks, h4rsx, this was a very interesting stove to me, and I tried to give it a very thorough review.

      HJ

      Delete