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Soto OD-1R Canister Stove Product Review

This Japanese stove is small, light, and well-made, with a unique miniature pressure regulator instead of a needle valve.

Overall Rating: Average

It's small, light, well-made, and works reasonably well, but its CO emissions are definitely too high for comfort. The marketing claims for the merits of the pressure regulator valve are misleading or worse.

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by Roger Caffin |

Soto OD-1R Canister Stove Product Review

Overview

There are many small upright canister stoves on the market with Western brands on them, and after a while one gets to recognise not just the basic designs used but also, in many cases, the Chinese or Korean factory the stove probably came out of. This stove is not one of those. It is made in Japan and the quality of the stove is uniformly high. The weight is at the lower end of the spectrum, the power output is good, and it has an integrated piezo-igniter system. Its chief claim to fame however is the unique 'valve' system used. It does not have the conventional needle valve: it has a miniature pressure regulator instead. We will review the various features in turn, with the pressure regulator given extensive coverage at the end.

The piezo-igniter seems well made. The interesting bit is that the insulated high voltage wire goes up the inside of the burner column to emerge at the top of the burner. You can see a small, bright, pointy bit right at the top of the burner head: that's the spark gap. This means that the wire and spark gap are well protected from damage. The metal housing around the piezo mechanism itself seems tight and compact. How long the spring mechanism inside the housing and behind the button will last - that I do not know.

It has been claimed that a piezo-igniter (any brand) will only work up to 2,000 - 2,500 meters (6,000 - 8,000 feet). Part of the reason for this is that there is only so much energy in the spark, and if the air and the gas is very cold, the spark may not be able to ionise the gas and break the molecules down. Whether or not this is strictly correct, there is no denying that it might be a smart move to always have a spare lighter (or two) at any altitude.

In use the stove has to be operated slightly differently from other stoves. With a conventional needle valve, you turn the valve off by screwing it in until it comes to a firm stop. With the pressure regulator, there is no firm stop. Instead, you screw the valve in until the flame goes out, then just a little bit further. To start a needle-valve stove, you open the valve from its easily-sensed closed position by a fraction of a turn. With this pressure regulator valve, you have to start winding the valve open and use the piezo many times as you go. Since you can overshoot on the shutting off (no hard stop, remember), it may take a turn or two before gas comes out. This can be rather alarming the first time you experience it (help, it isn't working!), but it's something you get used to after a few starts. For the rest of the control range, there is no real difference in behaviour.

SOTO OD-1R Canister Stove Product Review - 2
Morning tea on the banks of the Colo River, Wollemi NP, Australia.

The power output is claimed to be up to 3,260 W. I think that may be possible with a new canister on a warm day (when the canister pressure is high). Many other canister stoves claim similar power output - but need the same caveat. The claim by Soto that the stove will continue to perform just fine at -5 C (23 F) is seriously misleading however. The claim only works if the canister has an iso-butane/propane mix. If your canister does, then most any upright stove will perform just the same.

Not all brands of canister contain iso-butane: many contain n-butane instead. If your canister has n-butane then, just like any other upright stove on a new canister, it may work at -5 C (23 F) for a while - until the propane in the canister has been almost all used up. Then this stove will die, just like any other upright stove, leaving a canister two-thirds full of n-butane. The claim that owing to the regulator the Soto stove will boil water faster than any other upright stove at -5 C (23 F) flies in the face of basic physics and can be dismissed as marketing spin.

The pot supports are rather cute. You have to slide them up and down to open them out and lock them in position. There is even the word 'SLIDE' with a bidirectional arrow stamped on each arm to remind you. The sliding mechanism seems to work just fine. However, I do wish they held the pot a bit further from the burner, because of the CO emission.

SOTO OD-1R Canister Stove Product Review - 3
CO emission behaviour for the OD-1R stove

The CO emission spikes very high at start-up: almost 300 ppm when measured in the test system we have used for the CO series. It decays steadily, but even after a long time, it is still sitting over 100 ppm. The problem is the usual one of inadequate clearance between the burner and the base of the pot. Vendors often minimise this clearance in order to get slightly higher power output: marketing drive versus customer safety. The graph here shows that CO emission can be reduced by increasing this clearance.

It is worth looking at this problem in slightly more depth. A high level of CO means not enough oxygen (or air) is getting to the flame. Normally most of this air is sucked in through the air holes in the burner column by the high-speed jet of fuel coming out of the jet. The more powerful the jet, the more air gets sucked in. In most stoves the jet is quite small, allowing a high inner pressure P (see next section) to get the right amount of gas coming out - at high speed. But in this case it seems the range for the inner pressure P is lower, owing to design requirement of having the regulator work down to a low canister pressure. The lower pressure drop across the jet requires a large jet hole to get the needed gas flow, which means the jet speed is lower, which means that less air is dragged in through the air holes. To cut a long story short, the design decision to use a fixed regulator with a low output pressure range seems to have resulted in a slightly inadequate amount of air being sucked in, and a higher CO emission.

The instructions do mention The stove can produce carbon monoxide which has no odor and may cause death. The instructions do warn against using the stove in an enclosed space: a warning which should be heeded I think.

The instructions also say NEVER cover the stove with rocks and a windscreen while in use and NEVER surround the unit with wind shields. There is a diagram of the stove with a windshield half way around it and a big cross. I am not sure what 'cover' means, but any stove which cannot be used with a windscreen is pretty much useless in the field. I smell lawyers...

The Pressure Regulator - Reviewed

The novel pressure regulator used as the control valve is interesting. This regulator works well as a control valve, but there has been a lot of misleading marketing spin put about by various distributors selling this stove. The claims seem to be based on the marketing claims made by the Soto company - claims which, while not false, do tend to confuse reality. A lack of knowledge at the distributor end has compounded the problem. We will examine what is really going on here.

SOTO OD-1R Canister Stove Product Review - 4
The control system.

Inside the canister, there is gas pressure, which is a function of the composition of the fuel and the temperature of the canister. This pressure is far too high to go direct into any stove jet: it has to be reduced. This is normally done by the (needle) valve which presents a huge restriction on the gas flow, creating a pressure drop (down to 'P'). The greater the restriction or pressure drop at the valve, the less pressure there is left to push the gas through the jet, and so the less power comes out of the stove.

In other words, there are two places where the pressure is dropped between the canister and the outer face of the jet (which is at atmospheric pressure): across the control valve and across the jet. If there is a lot of pressure drop across the valve there is little pressure drop across the jet. If there is little pressure across the fixed-size jet there is little flow through it. It is identical to having two resistors in series or two taps on a hose.

It is crucial to understand here that the details of how the pressure is reduced (to P) by the control valve simply do not matter. All that matters is how much pressure is across the jet. A conventional needle valve varies the restriction or pressure drop across itself by varying the area of the hole around the needle in the valve, but this is not the only way this can be done. A more sophisticated diaphragm arrangement can be used for this: one which actually is designed to control the output pressure P per se. This latter is what is done in the Soto stove.

The marketing claim made by Soto is that the stove can maintain a constant power output as the canister pressure varies, and this is technically correct up to a point. The pressure P is regulated, and the flow through the jet depends directly on P. The claims made by some retailers and reviewers imply that the regulator will maintain a constant power output no matter what the pressure in the canister falls to, and this is seriously misleading (or false). The pressure regulator will only work while the canister pressure is high enough: it has to be a fair bit above P to be able to regulate. At this higher canister pressure, it does not matter whether a needle valve or a pressure regulator is used to get P. Below that, canister pressure the power output WILL fall.

The big difference is that using a pressure regulator rather than a needle valve means that P, and hence the flow of gas through the jet, and hence the power output, will be fairly constant despite a falling canister pressure. When using a needle valve, the intermediate P and hence the power output will vary. What the marketing claims do not examine is whether this constant power output matters in practice. I don't think it matters at all.

If I want high power (to bring water to the boil for instance) I open the valve so the stove is roaring away. If the power output varies a bit - who cares? If I am simmering, I turn the stove right down, but any small variations don't worry me either because I am usually monitoring dinner fairly closely and may be varying the power output as I go. To be sure, if I was running the stove for half an hour straight there might be some significant changes in the power output which might need correcting - but I never run the stove for that length of time.

Summary

The bottom line then is that the stove is nicely built, the piezo igniter works well, and the pressure regulator valve works very smoothly, but the CO emission is a bit higher than I am really comfortable with. The performance in the field does not show any special advantage to the unique pressure regulator valve.

Specifications and Features

Brand Soto
Country of origin Japan
Model OD - 1R
Power output (claimed) 3,260 W
Material Brass, aluminium, stainless steel, plastics
Size, packed 78 H x ~55 D mm (3.2 x 2 in)
Pot support diameter 110 mm (4.3 in)
Weight (claimed) 73 g (2.6 oz)
Weight (measured) 72 g (2.6 oz)
MSRP n/a, but retail US$65 has been seen

What’s Good

  • Well made
  • Light
  • Compact

What's Not So Good

  • High CO emission
  • Excessive and misleading marketing spin
Disclosure: The vendor provided this product to the author and/or Backpacking Light at no charge, and it is owned by the author/BPL. The author/Backpacking Light has no obligation to review this product to the vendor under the terms of this agreement.
 

Citation

"Soto OD-1R Canister Stove Product Review," by Roger Caffin. BackpackingLight.com (ISSN 1537-0364).
http://backpackinglight.com/cgi-bin/backpackinglight/soto_od-1r_canister_stove_product_review.html, 2010-03-23 00:00:00-06.

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Soto OD-1R Canister Stove Product Review
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James Eagleton
(toc) - F
My Soto on 03/31/2010 11:10:29 MDT Print View

Roger,
Thanks for the prompt response. I still think we do not know enough about the Soto. Let me add a few points.

1) On the stove box, Soto makes 2 comparisons to needle valve stoves.

a) Soto reports 1 L boil times for regulated vs un regulated (needle valve) stoves for 3 temperatures (regulated first): 20C = 4:02/3:54
5C = 4:01/7:42
-5C = 4:16/8:16 (min:sec) So, if you do not think Soto has not made any exaggerated claims, Soto should be the go to stove when ambient conditions are between 5C and -5C. Note, I made a mistake above, stating Soto only reported an advantage over a 5C temperature range. I can believe a 5C range but would like to see independent data to support the 10 C range. So, if Roger supports Soto's claims, I guess many of us will want to get the Soto.

b) Soto also claims a 25% decrease in gas flow for an unregulated stove over 8 minutes. I agree with Roger that this is an insignificant advantage. Soto says you will have boiled 2 L by then, and you probably should have started the stove at a 25% lower level to conserve fuel, and finally, you might be able to narrow the difference by opening the needle valve more. On the other hand, with a nearly empty can, the fuel cooling effect may put you in the low canister pressure situation where the bigger Soto jet is significant.

2) I just bought the Soto. The orifice looks much bigger than the 0.3mm jet on my Primus. It looks more than twice as big, but the Soto orifice does not look bigger than my 0.5mm pencil lead. Also, Primus makes other models with a jet diameter up to 0.45 mm. So, I can't say if the jet open area is more than 2.5 times a needle valve stove, or only a little bigger. If Roger is a good stove mechanic, he should be able to measure the Soto jet diameter.

3) I do not expect Roger to admit to blowing into the stove, I'm not going to admit it. None-the-less, I'm sure a clever guy like Roger could hook a balloon to the stove and get a general idea of gas flow rates at very low upstream pressure. I'm sure he will find that it takes very little pressure to lift the regulator valve, i.e. a "fair" pressure is insignificant, <0.1 atmosphere above ambient. I'm not sure about the pressure drop across the fully open needle valve at reasonable flow rates. You could easily extrapolate very low pressure flow rates up to cold cylinder pressures.

4) The composition in the cylinder gas mix does not have large effect on the advantage of the regulator stove over the needle valve stove. You could take off the cylinder that produced the faster boil times in Soto's tests and replace it with a high propane cylinder that gives the needle valve stove equivalent performance to the regulator stove from 5C to -5C. However, if you lowered the test temperatures to another range, say -7C to -17C, you would see the same relative performance difference, because the cylinder pressures are equivalent. Again, although Roger supports Soto's claims, I want to see the data.

Cheers,
Jim
p.s. I have not bought a cylinder for my stove and do not expect to see a 0C ambient temperature for a long time. So, I can't do burn tests.

Kerri Larkin
(Bumper) - MLife

Locale: Coffs Harbour
Top Spot! on 04/01/2010 01:03:52 MDT Print View

Hi Roger,

Nice review, as always. Just spent my first night camping in Wollomi - never knew it was such a top spot. I'll be there again.

Kerri

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: operation in cold on 04/01/2010 04:52:17 MDT Print View

Hi Jerry

> On the Soto website they have a video showing how the stove maintains flow
> when you put the canister into ice water.
> This seems like marketing hype to me.
First of all, the claim that the stove maintains the flow is certainly wrong. The flow is driven by the gas pressure inside the canister.

That said, the video is quite possible - with the right canister. You see, ice water sits at 0 C, while iso-butane boils below -10 C. So a canister of isobutane sitting in ice water will contain gas above the boiling point, and it will work. Just don't try it with pure n-butane, which boils at 0 C.

> I think a MSR Pocket Rocket would be a better buy
Sorry, but I regard that stove as one of the least reliable ones. The pot supports are very bendy, and the flame is far too focused. Now the Snow Peak uprights and the Vargo Jet-Ti - they are reliable.

Cheers

George Matthews
(gmatthews) - MLife
Re: Re: Soto OD-1R Canister Stove Product Review on 04/02/2010 19:42:20 MDT Print View

Great review as usual. Timely too.

Their marketing is interesting. Recently got an email and then reread your article. Glad we have you to review CO2 for those of us that live 'dangerously' out of the weather : )

Thanks for enlightening us!

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Re: Re: Soto OD-1R Canister Stove Product Review on 04/02/2010 20:12:10 MDT Print View

I think Roger gets more interested in Carbon Monoxide rather than Carbon Dioxide.
--B.G.--

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Re: Re: Re: Soto OD-1R Canister Stove Product Review on 04/03/2010 17:38:50 MDT Print View

> I think Roger gets more interested in Carbon Monoxide rather than Carbon Dioxide.
Well, with Rog and Dean looking after the CO2 market, there's no room left for me there ... :-)

Anyhow, CO can kill, but you need CO2 to live.

Cheers

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: My Soto on 04/03/2010 18:03:25 MDT Print View

> a) Soto reports 1 L boil times for regulated vs un regulated (needle valve)
> stoves for 3 temperatures (regulated first):
> 20C = 4:02/3:54
> 5C = 4:01/7:42
> -5C = 4:16/8:16 (min:sec)

OK, I am going to give this my full unexpurgated blast.
This is totally meaningless marketing spin. When companies come up with stuff like this my reaction is to assume that they are fudging everything.

Why? several reasons:

First, no test conditions are given. I can make any stove look the best by fiddling the test conditions. Dead easy.

Second, if the claim is to be taken at face value, it still has nothing to do with the regulator. Rather, it has to do with the gas flow settings and the burner face.

If you don't believe me, then I have some unique quantum crystals which will enhance your life and reduce your pack weights for private sale at really special prices ...

> Soto also claims a 25% decrease in gas flow for an unregulated stove over 8 minutes.
Again, this is meaningless marketing spin. No test conditions are given. I can reproduce this under suitable conditions (like a nearly empty insulated canister) - but so what? Anyone who sets his stove and walks away for 8 minutes is a raving loony. Anyone with an ounce of sense monitors his stove while it is running, and adjusts it as needed. Straw man!

> with a nearly empty can, the fuel cooling effect may put you in the low canister
> pressure situation where the bigger Soto jet is significant.
I understand the theory, but experience says the effect is insignificant. I have emptied so many canisters in the field with my Snow Peak GST-100 (and many other stoves) without any problem at all. Let's look at this one in more detail.

First, there is the phase where the canister is nearly empty - just a little cold liquid left. OK, it's getting colder - so I put my hand on the canister for a minute to warm it up, or I pour a few teaspoons of luke-warm water over it. No problem. There are many ways to keep the pressure inside the canister fairly high.
Second, there is the brief phase when the liquid is all gone and all that remains is gas at pressure. This phase is very brief in practice. Just open the needle valve up. You are going to have to replace the canister very soon anyhow.

SOTO have produced a stove which has a different control valve. Obviously they want to sell lots of their product. So the marketing guys are set to work to come up with every great advertising story they can think of. But just because they have lots of stories does not mean any of them have real meaning, nor that we should blindly accept them. Crystal healing anyone?

In practice, in the field, there is no perceptible difference between the SOTO control valve (implemented with a micro-regulator) and any other control valve (implemented with a needle valve). They are all control valves. Read the technical section in the article on the Regulator valve to see why.

Cheers
PS: sorry James - by now I'm a professional cynic. :-)

phil maher
(showkiller) - F
Always a pleasure on 04/19/2010 20:03:24 MDT Print View

Hi Roger,

I never did get the ice water test...if it's still liquid, it aint frozen, and 32F just barely squeaks you down to the boiling point of the n-butane. How silly! And the "flag" goes up again. I want to buy one just so I can pop it and a canister in my freezer for a week and then see what happens (I won't ask you to join them, but always did want someone to tell me if the light goes out when you close the door...it might even be brighter with an OD-1R in there). Annecdotally...the local REI has a ton of these that have been languishing on their shelves for months now. If only I had so much faith in the average canister stove buyer...but alas, I'm sure they'll start flying out the door when the season gets going and everyone decides that the cool looking little stove is the one the want and need to get them through their frigid summer adventures.

Edited by showkiller on 04/19/2010 20:26:20 MDT.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: Always a pleasure on 04/19/2010 23:08:32 MDT Print View

Hi Phil

Yeah, my understanding is that the REI order was what got them launched in the USA.

BUT, make no mistake about what I am saying. The OD-1R is a nicely-made stove, albeit with a slighty higher CO emission than I like. It's the marketing spin from the retailers which is total crap.

Cheers

phil maher
(showkiller) - F
rere: always a pleasure on 04/20/2010 09:15:06 MDT Print View

I fully agree- it is a well made little stove. But then again, so are many made by companies that have been doing this since well before 1992. Soto is guilty of allowing this to happen, either through omission, or by strategic plan. Clarification of the stove's true capabilities and limitations is their responsibility entirely. A sustainable reputation is built and maintained through the test of time, not by hype and capitalizing on misinformation down the retail chain. We have banks for that.

Connie Dodson
(ConnieDodson) - F

Locale: Montana
simmers on 05/15/2010 20:48:38 MDT Print View

Okay, almost empty cartridge, runs smoothly, simmers.

For ordinary use, for backpacking, does it's job.

Don't use this stove in your tent.

I don't use any backpacking stove in an enclosed area.

John Swarbrick
(johnboy) - F
CO production on 03/24/2011 20:17:49 MDT Print View

Roger,

Have you measured the Co production of the appliance in a vitiation chamber? Or is the assertion the the Co production will be higher based on the fact the applaince is using a larger than 'normal' injector diameter??

Hikin' Jim
(hikin_jim) - MLife

Locale: Orange County, CA, USA
Re: CO production on 03/14/2013 20:37:07 MDT Print View

Soto has or is about to introduce a new version of their Microregulator stove, the OD-1RX. Supposedly, from what I've read, they've reduced pot clearance in the new version in order to improve heat transfer in wind (indeed, the new version is referred to as "The Wind Master"). Reduced clearnance could be a bit of a problem in terms of CO production.

HJ
Adventures In Stoving

stephen korpi
(sk@mountainshop.net) - M

Locale: Portland Oregon
Cold Weather Performanc on 08/31/2013 16:05:52 MDT Print View

My experience with the Soto Micro Regulator stove is limited to only several hundred uses in the Pacific Northwest. Using this stove at relative altitude and freezing cold temperatures, I can assure you that my experience is markedly different from the reviewer. In my opinion, the stove works exactly as advertised, and being involved in search and rescue, I have had the opportunity to compare it to many other stoves in the exact same conditions. I shove my canister into the snow, fire up the stove and sit back and relax while those around me are trying their best to keep their canisters warm, using insulated koozies, pans of water, or in the case of the Jetboil, holding it in their hands. The only downside I have experienced with this stove is that because of the regulator, the flame stays consistent until seconds before the canister is empty, rather than the extended drop in output on un-regulated stoves.

jerry adams
(retiredjerry) - MLife

Locale: Oregon and Washington
Re: Cold Weather Performanc on 08/31/2013 16:10:47 MDT Print View

what about when those others shove their stoves in the snow?

Ken Thompson
(kthompson) - MLife

Locale: Behind the Redwood Curtain
Re: Cold Weather Performance on 08/31/2013 16:10:53 MDT Print View

I see that Stephen sells these stoves over at Mouuntainshop.net

Your first post here should have that disclaimer.

stephen korpi
(sk@mountainshop.net) - M

Locale: Portland Oregon
Re: Re: Cold Weather Performance on 08/31/2013 16:39:45 MDT Print View

Disclaimer: I work at a shop that sells the awesome things you use.

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Re: Re: Cold Weather Performance on 08/31/2013 16:41:43 MDT Print View

"Disclaimer: I work at a shop that sells the awesome things you use."

That's great. I have lots of other friends who work at REI as well.

--B.G.--

stephen korpi
(sk@mountainshop.net) - M

Locale: Portland Oregon
Re: Re: Cold Weather Performanc on 08/31/2013 16:57:18 MDT Print View

Jerry, In my experience, non-regulated canister stoves have a significant drop in heat output when the canister is subjected to freezing temperatures. Keeping the canister warm can mitigate this. Conductive heat loss from the snow is relatively easy to avoid. A homemade foil/foam koozie is lightweight and inexpensive, but it is most effective when you are starting with a warm canister to begin with, as it will not warm up a cold canister. Another method can be using a hand warmer in the concave depression on the bottom of the canister. You would still need some sort of insulator between the canister and the snow. You can also put the canister into a pan of liquid water. This will keep the canister above 32 degrees for a while until it freezes. I speak from experience because I have used all these methods for other stoves until I got the Micro Regulator. Since I don't have to worry about cold weather performance, all I have to do is shove my canister into the snow, and I have a perfectly stable stove to melt snow.

stephen korpi
(sk@mountainshop.net) - M

Locale: Portland Oregon
Re: Re: Re: Re: Cold Weather Performance on 08/31/2013 17:09:49 MDT Print View

REI certainly has it's market in more mainstream brands. Some of those brands have done a decent job with lightweight gear, with more to come in the future. For many people in the country, REI is the only place to put your hands on gear, but there are many cottage companies that do not sell to REI. If you to check out an ultralight tent, your options are ordering it online, or finding a small shop that supports those companies.