Stove Test – Pot Base Diameter vs Boil Speed

[bradmacmt]

Brad, it is interesting you created that windscreen for that Snow Peak stove when Snow Peak created one almost identical but made from stainless.

Snow Peak’s little windscreen for the Giga was a bit of a joke. It barely had any vertical surface to protect the burner, didn’t work all that well, and was heavier, hence the MYOG project. I suspect SP made theirs as they did out of an abundance of caution. I used theirs to trace the cutouts on mine.

[bradmacmt]

I believe a lot of the JetBoil disdain is because of the weight. It is relatively easy to design a super efficient system for boiling water/cooking. However, when you consider the weight, you find that efficiency comes at a weight penalty. An alky stove at 1/2oz, a windscreen at 1/2oz and a pot/lid at 3.25oz with a concentric ring heat exchanger gives you a fairly efficient system for boiling water and other light cooking chores. So, 11oz vs 4.5oz not counting fuel containers.The roughly 6oz will go a LONG ways towards efficiency when the difference is only 4gm…about 3 weeks. Nobody really cares about the time, after all, it is all camping out.

While I believe it’s true about the weight being an obstacle for some, my Sol Ti weigh’s 8.68 oz’s, and Sol Aluminum version weighs 9.59 oz’s, so not really 11 oz’s. Also, I do like that it creates a small “package” of cup, bowl, spoon, fuel, stove and pot. Space means something and I prefer having a bowl and mug integrated with the main cooking pot/stove. And, while I may be the odd man out, I actually do like having water boil relatively quickly when backpacking. There are so many other things to do that cook. And I really dislike the “fiddle factor” of alc stoves.

Here’s my JB “all-up” cooking/eating package. Jetboil Sol Ti, A Snow Peak Ti bowl, Snow Peak mug (from their “Ti Mini Solo”kit) which nests perfectly around the base of the Jetboil, and a folding Snow Peak Ti Spoon. It all goes into a .28 oz mesh sack.

 

[Michael B]

I believe a lot of the JetBoil disdain is because of the weight.

Yep, I agree.

It is relatively easy to design a super efficient system for boiling water/cooking. However, when you consider the weight, you find that efficiency comes at a weight penalty.

It may be easy to design around a fixed operating point, which is what Jetboil has done (boil water fast), and has done at a weight penalty, as you say.

An alky stove at 1/2oz, a windscreen at 1/2oz and a pot/lid at 3.25oz with a concentric ring heat exchanger gives you a fairly efficient system for boiling water and other light cooking chores. So, 11oz vs 4.5oz not counting fuel containers.

I am with you, but many people do not want to use an alcohol stove, and many places ban their use, so that is off the table for many people.

The roughly 6oz will go a LONG ways towards efficiency when the difference is only 4gm…about 3 weeks.

I’m not exactly sure what you are saying – perhaps you are inferring that a less efficient alcohol stove will still be better in most cases because of the weight savings. If so, sure.

Nobody really cares about the time, after all, it is all camping out.

There is clearly disagreement with you in the market, as almost all stoves make some sort of claim about their ability to boil a certain amount of water in a given time period. Clearly the marketing folks believe that people care about time. But I agree with you from my point of view. I’m camping. I don’t care if my water boils in 6 minutes, 3 minutes, or 10 minutes, unless that time is costing me fuel.

Snow Peak’s little windscreen for the Giga was a bit of a joke. It barely had any vertical surface to protect the burner, didn’t work all that well, and was heavier.

I would disagree with you there. If you paired their windscreen with their appropriately sized pot (I believe the 1.4L) their is a minimal gap between the top of the screen and the bottom of the pot, and I have never had any issues with its usefulness. I agree though, why stainless and not titanium like all the ti pots? weird choice of material. I suspect maybe they thought it would be a better heat barrier with the weight, so the heat would rather go to the pot than down to the canister. I don’t know. As a product designer, I always love to hear other designers describe their goals and their input requirements. Unfortunately I don’t get to hear about those as often as I’d like for some products.

 

 

[Michael B]

Also Brad, I really appreciate you doing the tests. I only have my giga power stove and some alcohol burners I’ve been playing with. I don’t find a useful reason for me to go get a different stove since the giga works great and will likely last longer than my desires to backpack. I do, however, like saving fuel, and modding stuff keeps me interested, so more data points to look at is always better!

 

[Jon Fong / Flat Cat Gear]

Here is a chart plotting isobutane fuel consumption verses theoretical efficiency.  All of this can be calculated, it’s all physics.  The amount of energy required to heat up water is the Specific Heat of Water: 1 cal/gC.  Isobutane contains 108000 cal/g (Zenstoves).

If you are boiling 500 ml to boil (at sea level) and consuming 12 grams of fuel, you are running at 30% fuel efficiency.  If you slow down the burn rate and boil 500 ml using 6 grams, you are now running at just over 50% efficiency. Slowing down you burn rate will save you 50% on the fuel consumption.

As you can see, there is also an asymptote: 100% efficiency is reached at 3.5 g of fuel to boil 500 ml.  Anyone who claims better fuel efficiency than that is violating the Laws of Physics.  If you look back at some past threads. SimmerShield was claiming that their system (lab conditions) could boil 13.5 liters of water using a single 110 g canister.  That equates to a 91% fuel efficiency based upon 13.5 l & 110 g of gas, This does not include start and stopping for multiple burns due to the limited mug volume.  Again, physics does not lie and this test results are highly suspect (IMO).

[Roger Caffin]

I usually assume 50% efficiency for a medium flame. I have run higher efficiency, but that was when I was low on fuel (a mistake when packing).

SimmerShield might have been doing what Jetboil did with their first release at an OR: started with quite warm water and said the water was boiling when it was emitting bubbles (which were dissolved oxygen). This was reported here at BPL, and Jetboil took down their claims a few days later. HA!
Was this Jetboil being deliberately deceptive, or was it just marketing guys being typically ignorant. Realistically, I incline towards the latter.

Cheers

[Michael B]

Yeah, but you cannot ever reach 100% in reality, as the system is not closed. It is always losing heat to the environment and this amount is going to vary with the given environmental conditions. At some point, reducing the input will just be emitted into the environment as a net zero. Given our selection of stoves, the granularity of the throttle on most of them is not going to allow us to reach that point in practicality, but something to consider, as there is likely some happy medium performance point for most of our backpacking needs.

[Jon Fong / Flat Cat Gear]

I totally agree with you.  My belief is that a number of people are caught up in the JetBoil marketing spiel: damn the torpedoes, full speed ahead!   Now if that is what you want to do, that is fine by me, just be aware of the cost: in this case, it is excess fuel consumption (weight).  Knowledge is power and you have the choice as to what is best for your situation, I prefer to focus on efficiency.

[Casey Bowden]

I’ve not seen that chart before, thank Jon.

I’ve used the chart to estimate the efficiency of your Sterno Inferno hack which you tested to use 4 grams to boil 2 cups (473 ml) of 70 degree F (21.1 C) water.

Estimated Fuel = 4 grams x [500/473] x [21.1/20] = 4.5 grams

Efficiency (from chart) = 75%

[Jon Fong / Flat Cat Gear]

I found an slight error in the formula (my bad).  This is the corrected chart.

[Michael B]

I totally agree with you.  My belief is that a number of people are caught up in the JetBoil marketing spiel: damn the torpedoes, full speed ahead!   Now if that is what you want to do, that is fine by me, just be aware of the cost: in this case, it is excess fuel consumption (weight).  Knowledge is power and you have the choice as to what is best for your situation, I prefer to focus on efficiency.

I don’t think, in general that Jetboil systems burn less efficiently, but they do weigh more, is that what you were trying to say? Or did I miss something? I think the people that enjoy those systems like not having to fiddle with putting their own kit together, or they like how all the pieces fit neatly together. It’s obviously worth it to some, I refuse to believe all Jetboil owners are lemmings :)  We all use what keeps us hiking, regardless of specs.

[Jon Fong / Flat Cat Gear]

@Casey

Estimated Fuel = 4 grams x [500/473] x [21.1/20] = 4.5 grams

Close

Estimated Fuel = 4 grams x [500/473] x [(100-20)/(100-21.1)] = 4.29 grams

[Jon Fong / Flat Cat Gear]

@Michael,

I don’t think, in general that Jetboil systems burn less efficiently, but they do weigh more, is that what you were trying to say?

 

What I meant was a lot of people want to compare other cooking systems to JetBoil and in particular, time.  JetBoil does a great job of that, hands down.  They are also heavier and in the case of the Stash. I believe that they took a step backwards in wind resistance.  If I am going to compare other cooking systems to JetBoil, I would go after fuel efficiency in a low weight system.  And by fuel efficiency, I mean in real usage including ambient wind.  I do not care about speed.  My 2 cents.

[Michael B]

You are probably right about the stash, it looks like they are trying to capture a little of the UL market with a “lightweight” system. They’ll probably sell a ton.

[David Gardner]

I have many lightweight to XUL alcohol, Esbit, and canister kits, and have owned or tested many others, including a Jetboil. About 10 years ago I needed an alpine adventure stove, so I gritted my teeth and paid the king’s ransom demanded by MSR for a Windburner.

Gave the Jetboil to my brother about two weeks after an early spring one-night backcountry ski trip with an adventure buddy to ski off the peak of Mt. Dana. Fair weather being in the forecast we did not take a tent. I had a 7 pound arctic down bag with a Gore-Tex shell. My friend had a down mummy bag rated to 15°F and a bivvy. We were each self-sufficient in case we got separated. He had a Jetboil and I had my Windburner.

The plan was to get to our campsite above tree line in the early afternoon, but we had some equipment problems with our climbing skins on the way up and didn’t get there until almost dusk. As my friend was taking his sleeping bag out of his pack he discovered that his water bladder had leaked and parts of the bag were wet. It wasn’t soaked, and only maybe 20% was wet or damp. It was getting dark, he had his bivvy and the weather was clear. So we set up where we were. And of course some weather moved in. It got windy and he got cold. We huddled and he tried to heat some water with his Jetboil. No way. Dug out my Windburner. No problem.

The Jetboil is a great stove. Efficient, reasonably light for what it is, not outrageously priced.

The Windburner is expensive AF and a hog at almost a pound.

But in winter, or any other situation where hypothermia must be anticipated (spring backcountry skiing or rafting for instance), when I might need to rely solely on my stove for survival – alone, everything soaked, raining or snowing, windy, no shelter, exposed, broken limb or otherwise unable to move or relocate, getting close to full blown hypothermia and fingers barely working – the Windburner is literally a lifesaver. Nothing comes close to its ability to heat water quickly under any conditions and get it inside me.

It does not require any other windscreen or more than a 6” diameter place to sit, and it will boil water. No matter what. Sitting on a rock at altitude on an exposed alpine ridge, winds gusting over 40 mph, it will boil water. Under even worse conditions it will still heat water hotter than you can drink. In minutes.

Without meaning to be overdramatic, when weight and efficiency are not the most important criteria, and you want to do everything possible to make sure you get home to spouse, partner, children, family – to the rest of your life – the Windburner is in my experience by far the best tool for the job.

[Roger Caffin]

I am sure the Windburner heats water well. Just remember however that it emits a lot of CO from the Reactor stove it is based on. Do not use it inside any enclosed space.

Cheers

[David Gardner]

+1

Based on, but the burner is somewhat different I think. Don’t know if it makes much difference.

Myself, with the Windburner, I don’t need to put it in the tent pretty much regardless of outside conditions. Glad to burn a few extra grams of fuel to totally avoid any possible CO2 or carbon monoxide.

[Roger Caffin]

I get the impression from the MSR web site that it is basically the same burner. It always was a dangerous CO bomb, and they know it (because we told them with proof).

Cheers

[Eric Blumensaadt]

I have used an anodized aluminum 3 cup Open Country pot for years. It came with my Trail Designs ti Sidewinder stove.

Its height-to-width ratio of 2.5″ by 5″ seems ideal for maximum efficiency. I have had excellent results with it using both alcohol and ESBIT tablets.

It’s pretty well known that tall. narrow pots are not as fuel efficient as lower, wider pots, volume being equal. Is a 2:1 width to height ratio ideal? Works for me.

So… why does JetBoil use a tall pot? Likely it is determined by limits needed for the stove width.

[James Marco]

Well, I get very good results from a Stanco GS1200 Grease Pot. It is 5.625″Dia x 4″ and holds about 40oz, though I never fill it that full. It will fit a full Liter/qt and leave a bit of room for cooking. The weight is OK out of the box, but you can modify it easily:
1) Use a smaller screw on the top handle with a plastic tube for a handle.
2) Toss the strainer (or use it to boil coffee in a full pot.)
3) Cut the rim off the top and mount it upside down. (You can also step on the handle on a stock lid to reverse the “dish” and mount it upright.) This will allow all condensation to drip back down into the pot.
4) After annealing the bottom, it is possible to press a series of ridges into the bottom to act as a “sort-of” heat exchanger. (It actually increases the surface area for heat absorption and increases friction by increasing gas turbulence…~15% increase in efficiency.)
5) A wind screen/heat shield can be made from two layers of aluminum foil.(Size appropriate to your burner.)

Eric, I don’t think the ratio is all that important. 5-6 inches seems to be the most efficient diameter for our small camping burners without running at higher less efficient heats. Aluminum to maximize conduction. Low mass (as light weight as possible) to eliminate the heat sink.

You can use a high heat thermometer to find the best heat on a propane/butane burner. Simply place it around the edge of the pot without touching the pot. You should register about a 250F/120C as the heat rolls over the edge giving you about a 9-10 minute boil for 2 cups/500ml.

[Michael B]

Minimizing the diameter in theory will reduce the heat loss out the top of the system, but I suspect the sizing of jetboil systems has to do more with the packing efficiency than anything else, they probably sized it around the canister size they expect most users to use for a given system. My best guess.

[Roger Caffin]

Minimizing the diameter in theory will reduce the heat loss out the top of the system
In theory.
But in practice, the heat loss from the sides of a pot is very small. Bring a pot of water to the boil with a lid on it (!), turn the stove off, and see how fast it cools (with the lid still on).

Far more important is the area of the pot bottom: the bigger it is, the more heat gets in from the flames.

Cheers

[Michael B]

In theory.
But in practice, the heat loss from the sides of a pot is very small. Bring a pot of water to the boil with a lid on it (!), turn the stove off, and see how fast it cools (with the lid still on).

Far more important is the area of the pot bottom: the bigger it is, the more heat gets in from the flames.

I agree on both points, but I’ve never bothered to check my pots for how quickly they cool. If I were designing a product to sell and wanted hard numbers to advertise, you can bet on the fact I would have ALL the numbers I could muster.

[Chris R]

When I stated backpacking/camping over 20 years ago, pots were, well, pot shaped! Seems to have changed at some point so that everyone wants  to bring just one mug shaped pot along.

Was the introduction of the MSR Titan kettle the spark that started this trend or did someone else get here first?

They are certainly easier to drink from and maybe take up less room in your pack but folk just don’t seem to worry about the loss of efficiency

[Edward John M]

Downunder I started with tall skinny billy cans because that is what we used over an open fire, but the first pot I bought to go with the first stove I bought was the SIGG and I still think that wide but flared shape is the optimum for use on a stove.
I think they fell out of favour because that were a little awkward to pack and not because they didn’t work well

[Author]

Posts