Lightweight Integrated Canister Fuel Cooking Systems State of the Market Report 2011: Part 1 – Overview and Performance Evaluation

[Levon Jensen]

awesome review, made my purchase easier haha:P

amazon has the jet boil ti on 25% off right now for anyone on the fence about buying one.

[Hikin’ Jim]

If I'm reading this chart correctly,

It took about half the time (roughly 200 seconds vs. roughly 400 seconds) for stoves with regulator valves to boil water in cold, calm conditions than stoves with a needle valve. Am I not reading that chart correctly?

What would account for this? The very same stoves do not show this difference in time to boil under warmer conditions. If it's not the regulator type valves, then what is causing these three stoves (Sol Al, Sol Ti, and Reactor) to boil water in half the time than the others (Eta Solo, PCS, Zip, and Flash)?

HJ

[John Vance]

I have moved from an Optimus 8R through pretty much everything including cat stoves. The latest has been a Sol ti and I couldn't be happier. Much faster than my PCS, more fuel efficient, and burns evenly to the last drop. Did I mention that I don't have to cup the cannister in my hands to keep it going in cold temps?

[Roger Caffin]

Hi Jim

You are correct. The Jetboils do not go too well in the cold, while the small uprights work quite well. The reason is fairly simply: geometry.

With an open upright stove there is heat reflected from the flame and the pot back down onto the canister, warming it up and raising the pressure in the canister. More pressure, more flow, more oomph. In fact, that is why you need to monitor the temmperature of the canister when cooking, to make sure it does not get too hot (ie hotter than you can touch).

But with the Jetboils there is no heating of the canister. The underside of the stove acts as a baffle, blocking the heat and radiation. So the canister gets/stays cold, the pressure stays low, and the flame stays low. Long boil times.

The Eta Solo has the same problem of geometry, but it is not a great stove anyhow. The Reactor creates a LOT of IR radiation, and apparently some of it does get reflected back down. More than I had expected in fact. It also generates a huge amount of CO – take care.

As for the very long boil time with the Gnat in the wind: what do you expect? But no-one in his right mind would run the Gnat, or any other upright stove, like that in the wind without a good windscreen. Will's windscreen only goes half way around the stove (see picture); if you wrap the windscreen 9/10s of the way around the stove (as I always do) the wind has little effect.

Cheers

[Bob Gross]

"if you wrap the windscreen 9/10s of the way around the stove (as I always do) the wind has little effect."

Absolutely.

That still leaves a narrow slot for air induction, especially if it is on the downwind side of the pot.

–B.G.–

[Hikin’ Jim]

Roger Caffin wrote: You are correct. The Jetboils do not go too well in the cold, while the small uprights work quite well.

Take a very close look at that table of Will's. Exclude for the moment any non-Jetboil stoves — look only at the five Jetboil stoves. Two of the Jetboils work well in the cold (turquoise colored bars). Three do not. How can this difference be accounted for?

HJ

[Stuart R]

Jim – this is a test of boil time in cold conditions, so we can assume that the valves on the stoves are fully open. The only thing restricting the gas flow is therefore the jet. I don't have one to check, but I would bet that the Sol has a larger jet than the other Jetboils and this allows greater gas flow when the pressure in the canister is low. This will allow the Sol to work usefully a few degrees lower than the other upright stoves but will not change the fundamental lower temperature limit dictated by the gas mixture in the canister.

[Hikin’ Jim]

Hi, Stuart,

Thank you for that.

Will, in his testing specifications, does state that the valves were 100% open (except the Monatauk, where noted).

Will, in his article, mentions that the regulator valved stoves did better in cold-calm testing conditions than conventional valved stoves. His results bear that out: The Reactor, Sol Ti, and Sol Al didn't have a great jump in boil time from the warm-calm test to the cold-calm test where as all the conventionally valved integrated canister stoves did. The Eta Solo, JB Flash, JB Zip, and JB PCS all had quite an increase in boil times in cold-calm conditions over warm-calm conditions.

So, the explanation of the performance difference might lie in the size of the jet? I wonder if anyone has the means to confirm this? (I don't have an instrument to measure jet size).

I don't see any physics/chemistry reason why the regulator valved stoves are performing better in cold-calm conditions than the conventional valved stoves, but it'd still be nice to have confirmation that the difference is due to the jet sizes not the valve type.

HJ

[Hikin’ Jim]

Stuart:

If you have a moment, would you look again at Will's test results?

Notice that warm-calm results, the first bar in each stove's data, are all fairly similar for the first six stoves, somewhere between 150 – 175 seconds to boil*. Will specifies that the tests were run with the valve 100% open: "All integrated stoves were tested at full flame."

If the jet sizes are are larger on some of the stoves, how come the warm-calm results are so similar? Wouldn't we expect the stoves with larger jets to be faster?

If you look at the test results graphic again, there's a clear jump in boil times between warm-calm (the first bar) and cold-calm (the last bar) for conventional valved stoves. There is no such "jump" for the regulator valved stoves. What explains this performance difference? I don't think it can be jet size since the warm-calm results don't show the same pattern. I'm disinclined to believe the regulator valve is the cause, but at the same time I'm not satisfied that we've found a reasonable explanation yet.

HJ

*Actually, Will used a "near boil," but I'll say boil for ease of expression.

[Roger Caffin]

> Two of the Jetboils work well in the cold (turquoise colored bars). Three do not.

Indeed, and astute. However, I think the answer can be got from the pictures of the stoves shown in the article.
The Jetboil stoves using the older burner effectively mask the canister from any radiation, so in the cold the canister cools down even more (from evaporation) and the pressure drops. That reduces the flame size.
The two Jetboils which do not suffer in the cold are both using the new Sol burner. If you compare the Sol burner with the older one you will see that there are huge cut-outs in the Sol base, and the canister is clearly visible through those cutouts. This means that the canister can get both hot air and radiation from the flames of the Sol burner. The canister will therefore be warmer under a Sol burner, and the gas pressure higher.

Interesting. I wonder whether this was intended, or just coincidental. We will never know.

Cheers

[Hikin’ Jim]

Ah! Now THAT makes sense. I didn't think it could be a bigger jet since the stoves' boil times were all so close under warm-calm conditions.

I just googled some photographs of the new JB Zip and the Eta Solo. They do have some cut outs, but nothing like the cut outs of the Sol Ti and the Sol Al. The particularly large cut outs of the Sol might account for better cold weather performance.

A friend has a Sol Al. He and I will probably take it out tomorrow and see how it runs and what kind of warming the canister experiences.

HJ

[Stuart R]

"If the jet sizes are are larger on some of the stoves, how come the warm-calm results are so similar?"

Jim – this is where I think the regulator comes into effect. In warm conditions, there is plenty pressure in the canister so the regulator does what it is designed to do – regulate the gas flow to some predefined maximum rate, so all stoves heat the water at much the same rate (only the Reactor is faster). The contol on the stove may be fully unscrewed, but the gas won't come out any faster due to the regulator. It is therefore the action of the regulator that allows a larger jet to be used with a given burner head size (giving the benefit when the gas pressure is low) without excessively large flames or lift-off when there is adequate pressure.

[Roger Caffin]

> A friend has a Sol Al. He and I will probably take it out tomorrow and see how it
> runs and what kind of warming the canister experiences.

Yes please! A report would be greatly appreciated.

Cheers

[Roger Caffin]

> The contol on the stove may be fully unscrewed, but the gas won't come out any faster
> due to the regulator. It is therefore the action of the regulator that allows a
> larger jet to be used with a given burner head size (giving the benefit when the gas
> pressure is low) without excessively large flames or lift-off when there is adequate
> pressure.

Agree, but everyone should note that you can achieve EXACTLY the same effect by simply adjusting the valve on the stove. A 'pressure regulator' and a 'needle valve' have EXACTLY the same effect on the gas pressure at the jet.

As with a propane system with its far higher tank pressure, the pressure regulator on these stoves is really just a safety device. Yes, it does allow the use of a larger jet size, but so what? A smaller jet gives the same gas flow when it has a larger driving pressure, and our propane/butane canisters have plenty of pressure (except when very cold, see below). The only difference is at those last few moments in the life of the canister, when all the liquid fuel has been used up and there is only gas left in the canister. Well, at that stage you are going to have to replace the canister in a minute anyhow.

There is a marketing myth promoted by some that a pressure regulator can somehow make a canister work *better* when really cold. That is a violation of the basic laws of physics, and just does NOT happen.

Cheers

[Hikin’ Jim]

> A friend has a Sol Al. He and I will probably take
> it out tomorrow and see how it
> runs and what kind of warming the canister experiences.

Roger Caffin wrote:
Yes please! A report would be greatly appreciated.

Cheers

A friend of mine recently got a JetBoil Sol (Aluminum), so over I went for a bit of testing.

As I've mentioned, I've been a bit curious as to why the various versions of the JetBoil Sol outperformed other stoves in cold-calm conditions. I also brought out a Reactor, another of the stoves featured in Will's report.

Our test subjects (front row):

As one might expect, the Reactor came to a boil first:

But this isn't a contest; I'm trying to understand why the Jetboil Sol beat out so many other stoves in Will's testing in cold-calm conditions. Roger has posited that the "cut outs" in the burner allow heat to radiate to the canister, and that the warmer canister accounts for the Jetboil Sol's better cold weather performance.

If indeed thermal transfer is occurring, then I ought to be able to detect it here:

The lower portion of the JetBoil Sol Al's burner was warm but still touchable by hand after about 15 minutes of operation.

By contrast, the lower section of the MSR Reactor's burner was too hot to touch after just a few minutes of operation.

Also, the canister of the JetBoil Sol Al did not noticeably warm to the touch after 15 minutes of operation.

I could feel a little bit of heat on the back of my hand when I held it as shown above, but nothing so great that I wanted to move my hand away.

Admittedly, feeling by hand is hardly the paragon of scientific rigor, still, if a significant amount of heat transfer were occurring either through the burner's attachment to the canister or via radiation through the cut outs, it ought to be detectable by simple manual means. I detected no such heat.

I'm inclined to think Stuart's aperture size conjecture may be where the explanation of the improved cold weather performance lies, although my simple tests can't completely rule out thermal conduction or radiation..

HJ

[Bob Gross]

Are you attempting to measure performance purely on the basis of speed to boil?

What about fuel efficiency, like grams of fuel used to boil a given volume?

Some people want speed, and some want fuel efficiency. Then equate that to stove carry weight. Nobody here wants a heavy stove unless it gains a lot in speed or efficiency.

–B.G.–

[Hikin’ Jim]

Bob:

Take a look at this graphic from Will's article:

Notice how most of the stoves had a much longer "boil time" (as defined in Will's article) when the boil was conducted under cold-calm conditions vs. warm-calm conditions. Note however that the two versions of the JetBoil Sol did not. Why did the Jetboil Sol do so much better than the other stoves in cold-calm conditions?

HJ

[Bob Gross]

Don't ask me. Ask the author.

I own only one of those stoves.

–B.G.–

[Stuart R]

"There is a marketing myth promoted by some that a pressure regulator can somehow make a canister work *better* when really cold"

Agreed, a regulator can't make any difference to the pressure in the *canister*, but it *can* make a difference to how the stove performs in the cold. As I posted on the previous page, a larger jet will allow a greater gas flow at a temperature a couple of degrees above the boiling point of the gas mixture, so the stove will have a good flame in this situation as opposed to a feeble flame on a conventional stove with a smaller jet. The regulator then kicks in in warmer temperatures to prevent the gas flow from getting too great for the burner head to handle. Of course, below the boiling point of the gas mixture nothing is going to get any stove to work.

[Paul McLaughlin]

Stuart – would it be a fair paraphrase of your point to say that the regulator equipped stoves (if also equipped with a larger jet) should have an advantage in a fairly narrow temperature range that lies near, but just above, the temperature at which the canister no longer has adequate pressure to deliver fuel to the burner? and that this advantage might be magnified when the canister is near empty?

[Roger Caffin]

Hi Jim

> By contrast, the lower section of the MSR Reactor's burner was too hot to touch after
> just a few minutes of operation.
> Also, the canister of the JetBoil Sol Al did not noticeably warm to the touch after
> 15 minutes of operation.
> I could feel a little bit of heat on the back of my hand when I held it as shown
> above, but nothing so great that I wanted to move my hand away.
> Admittedly, feeling by hand is hardly the paragon of scientific rigor, still, if a
> significant amount of heat transfer were occurring either through the burner's
> attachment to the canister or via radiation through the cut outs, it ought to be
> detectable by simple manual means. I detected no such heat.

Interesting, but not convincing. I was not suggesting that there would be a huge amount of heat coming down, just enough to warm the canister by a small amount – say 5 C. That you could feel some heat on the back of your hand is enough for me.

To go any further would require a temperature probe on the canisters. You might also need to do the test at sub-zero temperatures.

Cheers

[Roger Caffin]

Hi Stuart

> a larger jet will allow a greater gas flow at a temperature a couple of degrees above
> the boiling point of the gas mixture, so the stove will have a good flame in this
> situation as opposed to a feeble flame on a conventional stove with a smaller jet.
Hum, yes, but …
For the pressure regulator to work there must be a pressure drop across it. At the very least there will be a pressure drop due to the construction of the valve inside it. Will this pressure drop be greater than that across a needle vale which has been turned wide open? Normally I would think so, but I might be wrong.

As noted by OP, this effect only applies over a rather narrow temperature band, and I can't help thinking that the canister will often cool down right through that band when in use in the field. Which is why we use remote canister stoves …

> Of course, below the boiling point of the gas mixture nothing is going to get any stove to work.
Totally agree, and it is marketing spin which suggests otherwise which attracts my ire. Separate issue though.

Cheers

[Hikin’ Jim]

Suart Robb wrote: Agreed, a regulator can't make any difference to the pressure in the *canister*, but it *can* make a difference to how the stove performs in the cold. As I posted on the previous page, a larger jet will allow a greater gas flow at a temperature a couple of degrees above the boiling point of the gas mixture, so the stove will have a good flame in this situation as opposed to a feeble flame on a conventional stove with a smaller jet. The regulator then kicks in in warmer temperatures to prevent the gas flow from getting too great for the burner head to handle. Of course, below the boiling point of the gas mixture nothing is going to get any stove to work.

Stuart:

Your explanation is the most consistent that I've seen yet with the results of Will's tests. The difference in results in cold-calm conditions for the Jetboil Sol stoves is quite dramatic, dramatic to the degree that I doubt that the amount of heat I detected in my simple tests would account for it.

Of course at some level, we're still speculating. I wonder if Will might have the means at his disposal to measure the aperture of the jets used in his tests.

HJ

[Stuart R]

Alan – yes, almost. The stove with the larger jet should have an advantage over a narrow temperature range when the pressure in the canister is low. This is not 'magnified' when the canister is nearly empty, rather the temperature at which the effect should be apparent will depend on the canister contents. With a full Jetboil canister this may be around 0F, rising to around 15F as the canister is nearly empty.

Roger – I would think the pressure drop across a wide open regulator would be similar to a wide open 'needle' valve, and a good deal less than across the jet.

Jim – If you or anyone else has access to a JB Sol and some copper wires in the range AWG 20 to 30, it could help answer this conjecture to know which size of wire will just fit inside the jet.

[Tony Beasley]

>If you or anyone else has access to a JB Sol and some copper wires in the range AWG 20 to 30, it could help answer this conjecture to know which size of wire will just fit inside the jet.

I have access to a Profile Projector http://www.mitutoyo.com/TerminalMerchandisingGroup.aspx?group=1427 and I have measured a few stove jets with it, (a lot of jets appear to be laser cut) While I have a PCS and quite a few other upright stoves I do not have a Sol and at the moment I am saving up for a tramping trip to NZ and I am not willing to divert my funds to get a Sol (which are expensive in Australia), I also have a stove testing lab, with a canister temperature measuring probe and a flame profiler.

So if if someone is willing to loan me a sol (or even better donate one) for testing purposes I am happy to do some jet size measuring and stove testing to see what I can come up with.

Tony

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