BigLoad
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Post by BigLoad on Apr 22, 2019 20:13:15 GMT -8
I'm starting to see pots with a built-in heat exchanger that aren't part of an integrated system like the Jetboil or MSR Reactor. One example is the Olicamp XTS. I've also seen one from Primus that seemed heavier.
Olicamp claims a 40% boost in fuel efficiency. Has anyone here independently measured it? I'm having trouble seeing how it pay off on anything shorter than a week. The pot weighs about 2 oz more than an MSR Titan Kettle and although it seems compatible with most Olicamp stoves, it looks like the wingspan on the Ion is too small, so stove weight would also increase for me.
Calculations with alcohol stoves are so much easier, since you don't have the discontinuities introduced by going to the next size of canister or to a second canister.
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zeke
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Post by zeke on Apr 23, 2019 4:12:31 GMT -8
I guess it depends on how much hot water you want each day. Since I only used 12 ounces per day, I could get 12-14 burns out of a small canister back when I used a PR and the pot I currently have.
I'm sure you know about these tips, but I will list them here for anyone who is new-ish to the game. There are ways to stretch out the fuel, like sitting the water filled pot out into the sun for a while before dinner, warming the water to air temp prior to putting it on the burner. Good wind screens will also save fuel, but then one has to be careful about not heating up the canister too much. Just heating the water until the tiny bubbles form on the bottom of the pot (fisheyes) is all one needs to kill any bacteria in the water, and that amount of heat will also be sufficient to rehydrate any F-D meal. No need to wait for the full rolling boil.
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jazzmom
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Post by jazzmom on Apr 23, 2019 4:16:43 GMT -8
Comparing the same pot with and without the heat exchanger, the difference is only 0.4 oz (6.7 vs 6.3), so it's not the heat exchanger that's a big weight penalty. Fire Maple has the same pot, as well as some other styles (kettle, for instance.) I'm only seeing aluminum models though; maybe design/manufacturing issues in using titanium.
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Post by bradmacmt on Apr 23, 2019 5:26:25 GMT -8
maybe design/manufacturing issues in using titanium. There is... reference the baffles attached on the Ti Jetboil pots with their well documented problem melting off. Mine melted off. I will say, it was my own fault. I tried to actually cook an in-pot meal with mine rather than simply boil water. That's what did-in the pot. I disclosed this to JB, and they still to their credit gave me a new one out of their old inventory. They are no longer made. I have the Olicamp pot, as well as a pile of Jetboils. The fuel economy is real as many tests have shown, but you are right BL, you will not see a weight savings under a week. However, that's not the entire equation. The JB's do boil faster (at least my 4-11 year old versions), are more stable, and shed wind better than standard canister stoves. However, this year I plan on using a Toaks 650 ml Ti pot with the latest generation MSR Pocket Rocket Deluxe. It will make a combo of around 6 oz's, boil plenty fast, and use little enough fuel for my average-ish trips to make a real weight savings over even my Ti Jetboil.
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jazzmom
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Post by jazzmom on Apr 23, 2019 6:42:50 GMT -8
Yeah, in the same boat. My current setup is a Toaks 900ml at 3.6 oz and a Monatauk Gnat at 1.9 oz. They need to be able to make a much lighter heat exchange pot to make it worthwhile for me.
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BigLoad
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Post by BigLoad on Apr 23, 2019 6:43:09 GMT -8
I'm only seeing aluminum models though; maybe design/manufacturing issues in using titanium. I think that's it. My guess is that the heat exchanger element itself is hard to make in titanium, and the coefficients of thermal expansion are too different (a factor of 4 or 5) to be make a bimetallic structure that would survive frequent thermal cycling. There is... reference the baffles attached on the Ti Jetboil pots with their well documented problem melting off. Mine melted off. That's interesting. Was there visible melting? I figured it would be more likely to crack the welds.
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Post by Lamebeaver on Apr 23, 2019 6:44:27 GMT -8
A couple comments: 1. I occasionally cook over a real fire, and this pot wouldn't be an option for that. 2. Heat transfer on the bottom of the pot isn't generally a problem, most of the heat loss occurs as the flame is dissipated up the sides of the pan. I would think a heat exchanger such as the one below would be much more efficient, especially if combined with a wrap-around wind screen. 3. Unless you're exclusively boiling water, the bottom heat exchanger could lead to hot spots and burned food.
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gabby
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Post by gabby on Apr 23, 2019 15:02:56 GMT -8
I have one of those MSR heat exchangers (as pictured above), so I thought I'd "give it a go" and do the full-on efficiency thing, weighing the heat exchanger (HE) and the like, then testing it against a "true" integrated HE pot and the MSR HE on a few ti and aluminum pots, as well as timings on non-HE pots. However, I can't find the MSR HE, and I don't really have an HE pot other than the Primus 1L and 2.1L. (The 1L Primus weighs 10 oz on some websites - but pot has been discontinued, so no one could use one even if they wanted to. I thought I measured 9.<something> at one point or another in the last few months, but memory fails. I believe I said "9 ozs" in one of my thread videos, but ... FYI: I just weighed one of the ones I have, and it came out @ 261g/10.2 oz.) The weight most sites give on the MSR HE is 6 oz, but I somehow doubt that. I looked at a Fire Maple 1L HE pot that was 12 oz, but I don't, of course, have one to test. I didn't even get started toward my goal of doing the tests (collecting materials and gear and organizing the test), and, on top of that, it's probably ill-advised and wrong-headed, since I strongly suspect that the comments I saw all over everywhere on this topic of HEs are correct - that a windscreen was a better bet in terms of weight and performance. In addition, any sort of heat exchanger introduces strong limitations on use and a number of complications in use, and that's harder to quantify than the weight penalty. Except for very special circumstances, I doubt the difference in fuel use is really worth the extra complications, limitations and weight. OBTW dept.: I think the Olicamp XTS, just by its appearance, is actually the Fire Maple pot (with, perhaps, better quality control). A tip-off is that both the Olicamp and Fire Maple HE pots list 190g/6.7 oz as the "official weight", but a test I found - if I'm remembering correctly (because I didn't believe the manufacturer's weight - TGTBT, if you know what I mean) a review I found somewhere gave the measured weight as 342g/12 oz., which seems right. Given manufacturing variation, I wouldn't expect a weight more or less than the Primus. OTOH Subnote: SectionHiker's website gives 7.7 oz in a review, and he is impressed, at least with a canister stove: Earlylite August 28, 2012 at 3:00 pm Yep. 7.7 ounces on my scale. sectionhiker.com/olicamp-hard-anodized-xts-aluminum-pot-with-heat-exchanger/ And, P.S., great price @ Amazon! Finally, there are some relatively good reviews using the XTS and alcohol burners of the "center burner" type, at least when there's an appropriate space between the alky stove and the pot.
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ErnieW
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Post by ErnieW on Apr 23, 2019 18:49:04 GMT -8
A Ti heat exchanger constructed like the MSR above but smaller, sized for common pots like a Halulite would be good. Take it with you when you need it. Leave it home to save a little weight.
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gabby
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Post by gabby on Apr 23, 2019 19:06:09 GMT -8
Wheeeeee Hiram Cook strikes again... www.youtube.com/watch?v=5tpkd3tfCwkI'm stupid (duh), but the Sterno Inferno kit seems like a nice, cheap little pot - though it may be cheaply made (schlock? ya think?) It looks like straight aluminum (rather than anodized), but it's only $25 @ Amazon. I see that the Olicamp XTS is $23 @ Kenco in NY. In commentary at Amazon: The weight of just the cup with handle with lid = 171.5 grams/ 6.05 oz. The weight of just the cup with handle without lid = 114.9 grams / 4.05 oz. So, about 2 oz lighter than the Olicamp/Fire Maple, but probably a lot cheaper construction. And smaller. (16 oz. vs 32 oz for the XTS) ETA: Can you detect a wee bit of gear insanity here? 8^O
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BigLoad
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Post by BigLoad on Apr 23, 2019 19:29:31 GMT -8
Wheeeeee Hiram Cook strikes again... www.youtube.com/watch?v=5tpkd3tfCwkI'm stupid (duh), but the Sterno Inferno kit seems like a nice, cheap little pot - though it may be cheaply made (schlock? ya think?) It looks like straight aluminum (rather than anodized), but it's only $25 @ Amazon. I see that the Olicamp XTS is $23 @ Kenco in NY. In commentary at Amazon: The weight of just the cup with handle with lid = 171.5 grams/ 6.05 oz. The weight of just the cup with handle without lid = 114.9 grams / 4.05 oz. So, about 2 oz lighter than the Olicamp/Fire Maple, but probably a lot cheaper construction. And smaller. (16 oz. vs 32 oz for the XTS) ETA: Can you detect a wee bit of gear insanity here? 8^O
I haven't watched his videos before. I was impressed with how well-made they are. He packs in a lot of information without seeming rushed.
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ErnieW
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Post by ErnieW on Apr 24, 2019 11:49:39 GMT -8
A Ti heat exchanger constructed like the MSR above but smaller, sized for common pots like a Halulite would be good. Take it with you when you need it. Leave it home to save a little weight. I going to try my hand at making an aluminum version of that MSR exchanger sized for my Halulite. Aiming for as light as possible.
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gabby
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Post by gabby on Apr 24, 2019 15:05:07 GMT -8
I going to try my hand at making an aluminum version of that MSR exchanger sized for my Halulite. Aiming for as light as possible. Careful. As Hiram Cook says in at least one of his videos (there are a large number of them: he tested the "Inferno" stove with a hell of a lot of alcohol stoves, and then there are a slew of videos on the Olicamp XTS on his channel: Search Youtube with "hiram cook AND olicamp xts"), aluminum that's NOT "hard anodized" doesn't resist heat deformation if things get too hot, and a "heat exchanger" exists to get hot. "Getting hot" in order to transfer excess heat to the pot and its contents is its sole purpose." This guy (cited below) even "hacked" the Olicamp to get increased efficiency with a specific stove. He cut three gaps into the heat exchanger for the stove legs and increased efficiency by some 50%! (Video title says 40%, so...) Boys gotta play, though I really have no idea what this video actually means except for very specific uses, given the inherent limitations of HE pots already discussed. Mind, I like all this "playing around" with stuff for its own sake. Never know what you'll find. Montana Backcountry Adventure *Backcountryschlott*: Backpacking Hack for increased boil times (XTS Pot)
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zeke
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Post by zeke on Apr 24, 2019 15:33:00 GMT -8
I'm not looking for faster boil times. I'm searching for the quietest stove that uses the most readily available fuel. So far, that translates to an alcohol stove fueled with yellow heet, if nothing else. At least Heet can be found easily at most destinations I fly into, and any excess can be poured into the rental car.
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ErnieW
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Post by ErnieW on Apr 24, 2019 17:33:40 GMT -8
For me if the heat exchanger I am looking to make weighs about the same a normal windscreen and can basically also function as a windscreen and heat exchanger that item that is doing multiple uses. A windscreen is just a windscreen at least in my kit.
The other part is that there is a break point for the value of the exchanger. At the beginning of the trip it is just extra weight. But at some point a few days in the amount of fuel saved equals the weight of the heat exchanger. After that point the exchanger starts paying for itself. If it also boils water a little faster that is a bonus.
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