saving fuel

[layton]

Has anyone figured out the break even point between fuel use vs. weight on a pocket rocket vs. a reactor.

How many liters of water need to be boiled before the reactor becomes worth its weight?

 

If no one knows, I may begin this experiment. I'd actually like to try it with the new Soto stove.

 

Also, do you think that by heating less water, the use of heat would be more efficient since the water will be closer to the heat, or do you think that would waste energy?

[G-spotter]

You don't have to heat to boiling, you just have to melt

[hafilax]

The specs from MSR:

Pocket Rocket will boil 16L of water on one 227g canister whereas the Reactor will do 22L.

 

Need to know the weight of the pot for the Pocket Rocket to really compare. Assuming they are the same weight and you're just counting canisters.

 

<16L Pocket Rocket

to 22L Reactor

to 32 either

to 44 Reactor

to 48 either

 

To first approximation, the moment you will need more than one canister for the PR you might as well have the Reactor. The next approximation requires the weight of the pot used with the PR.

 

The lightest pots on the MSR site seem to be about 150g for 1.5L. Let's say that the PR system is about 250g and the Reactor 515g. The difference is about 1 canister so it seems that you might have to go to 3 canisters with the PR maybe?

 

Just a guess. Someone correct my quick analysis if it's wrong.

[ryanb]

The jetboil, though not as fast, wind cold or altitude resistant as the MSR will boil 11 L per 100g canister according to manufacturer specs (translates to 25 per 227) and weighs much less as well. I suspect it is the best choice in canister stoves for most cascade adventures. Particularly because I find a 100g canister will last me a weekend, non snow melting trip ...

[Choada_Boy]

The specs from MSR:

Pocket Rocket will boil 16L of water on one 227g canister whereas the Reactor will do 22L.

 

Need to know the weight of the pot for the Pocket Rocket to really compare. Assuming they are the same weight and you're just counting canisters.

 

<16L Pocket Rocket

to 22L Reactor

to 32 either

to 44 Reactor

to 48 either

 

To first approximation, the moment you will need more than one canister for the PR you might as well have the Reactor. The next approximation requires the weight of the pot used with the PR.

 

The lightest pots on the MSR site seem to be about 150g for 1.5L. Let's say that the PR system is about 250g and the Reactor 515g. The difference is about 1 canister so it seems that you might have to go to 3 canisters with the PR maybe?

 

Just a guess. Someone correct my quick analysis if it's wrong.

 

[video:youtube]

[layton]

I did the math using the dealer's specs.

 

I took the time it took to go through 100g of fuel, and divided it by the time it took boil one liter. By those calculations the Soto stove boils 24 liters of water on one 237g cartridge and the reactor boils 22. WTF? That has gotta be wrong.

 

I think the best thing to do is buy two full canisters of gas, time how long it takes to boil 32 degree water (by straining a slurry of ice water) and then time how long it takes the rest of the canister to run out while lit....then divide it out. I'll also do a side-by-side with a jet boil too.

 

unless of course someone has all three?

 

after that, i can figure out the breaking point, unless of course the jetboil and reactor lose to the soto?

[Choada_Boy]

Make sure you control for ambient temperature as well. Surface area of canister will also affect results, as will canister material and thickness. Do they both have the same flow rate when they are "full"?

[ryanb]

The jetboil boils much faster with a full canister then an empty and the sodo is probably the same way so if might make more sense to actually see how much water you can boil with different sized canisters.

 

The way I understand it, the jetboil design was optimized for fuel efficiency while the reactor was more optimized for consistent, short burn time and use in extreme conditions.

[hafilax]

I wouldn't do any tests starting from freezing (32F/0C) and going to boiling. Way more energy is required for phase transitions than simple heating and you wouldn't have much control over how much ice is in the slurry. I would do snow melting and water boiling tests separately.

 

There are other ways to improve efficiency: changing the pot and adding oil.

 

A thin layer of oil reduces evaporative effects as does having a smaller top opening.

 

Cooking pot experiments using oil and a pot with a small opening

[layton]

that's a great idea thanks!

 

Based on that article, would it make sense to make some sort of vase shaped pot with a super tight locking lid, an aluminum base, and a titanium side that would either be double walled with an air space you could fill/refill with a small amount of water and/or a superlight non-flammable coating on the outside of the pot. I don't think you would have a much heavier pot (1-3 oz maybe). You could add oil to non hot-drink meals to further increase the efficiency.

 

someone call msr

[layton]

or dane?

[Water]

this has been teased out to the n'th degree at backpackinglite as far as i can tell. also consider pocket rocket vs reactor, etc, the wind factor, if being used outside--wind screen weight and effectiveness. the reactor does a great job of this.

 

backpackinglite core members seem to get really uppity about using an 'upright' for cold conditions--touting the vast superiority of remote canisters-anything else for such conditions is 'stupid'. they also have gone through all sorts of usage issues and CO outputs, etc. Reactor does not come out on top all around in their book, other than being a powerful brute that is consistently fast and generally efficient (though a tad slower near the end of a canister, and not the most efficient). The main stove researcher there has serious misgivings about using a reactor in a tent compared to other stoves, due to CO issues (MSR supposedly redesigned their initial version of the Reactor after getting feedback from him regarding CO issues).

 

that said, I bought a reactor about a month or two ago without researching more than a few 'this thing rules!' product reviews (contrary to my rainman research for most purchases) and in my few uses for winter camping I've been thrilled with it. I find it much faster and easier to melt snow than the whisperlite i used previously. i think the thing kicks total ass and while poring over their forums and articles i sometimes second guess, but i know from the field the thing impresses me immensely (strictly for melting/boiling h20)

[KirkW]

might find this thread helpful as well

 

http://cascadeclimbers.com/forum/ubbthreads.php/topics/927523/1

 

+1 for the reactor. It works exactly the way everyone who owns one says it does. If you are planning on using it in the alpine you will not be disappointed. Not necessarily the stove I would carry if I was thru-hiking the pct but I think for melting snow and doing the alpine chef thing MSR fucking nailed it.

 

 

[Dane]

Sorry, Layton I don't have much to add.

 

I do use a foam "cup" on my gas cans for the Reactor made from a old pad. I thank Atreides for that idea. Although I use a small hole in the bottom you can set a BIC lighter too. Bowl with water might well be a better idea while cooking but I want a hot stove, fast and worry less about cooking more about melting. Haven't hooked up a heat exchanger to it yet. But eventually will I think.

 

Thought Colin Haley pretty much got it right in this comment, "Warm weather use a Jet Boil, Cold weather use a MSR Reactor."

 

For me it is more do I need a stove at all, If I do, I tried to break it down to three uses:

 

expedition base camp...white gas w/ a pump

winter climbing hydration..Reactor

summer (high % of time easy access to water)...Jet boil

 

I'd sure be interested in the results of any testing you do.

Although I use it I am not a huge fan of the Reactor. My concerns and observations are in the previous thread.

 

 

[powdrx]

This might be better in the topic that Atreides linked above, but I use the JetBoil a lot and really like it. I use the cup it came with and pour in a little hot water to keep the fuel warm and the flame roaring. Same technique Atreides uses with the Reactor and the squishy cup. I also bring a Nalgene gallon bag and fill it with lots of snow. Get the water nice and hot, but not boiling, and pour it into the bag to melt the additional snow. This works pretty well and I average ~12L of water with a couple boils from one 110g canister.

Admitted this is above 20F. I haven't used it below those temps. Just more food for thought from a JetBoil user!! Great discussion!!