Not much here, in keeping with the rest of my site/life. ;o
Here's some MVUM routes in Washington state that I planned out some years ago. Probably still valid-ish.
I post silly info about some of the hikes I've been doing recently, you can view it here.
Please note that I am not affliated with any products I might talk about here, other than owning them. I do not get kick-backs or amazon rewards, etc. I may link items just so you can SEE what I'm referring to.
Recently I bought a MSR Pocket Rocket 2 stove, and was curious about the efficiency of fuel used vs time to boil water. So I set up a little experiment, very unscientific. However, as silly as my experiement was, I did glean a little info that I didn't otherwise find on the innernuts souper hi-way. Everyone seems to just post about the time to boil water. Personally, I'm more concerned with how much fuel I burn when I boil water.
For the experiments I used:
--Jetboil "JetPower" fuel (a barely used 16oz (net weight) can)
--1.2L single-wall titanium cook pot, no lid used
--16oz of well water, at ~60° (new water with each test)
--Indoors, 70°, no wind, etc.
--Stove, attached to gas cylinder, is weighed multiple times to be as accurate as possible. In both ounces and grams (I used grams for my GpS calculation)
--Water is measured and poured into a room temp pot, then placed evenly on the stove's legs.
--Stove is lit at the most minimal flame possible.
--Stove flame is adjusted and the timer is immediately started.
--Digital temp probe is placed into the water, about 1/4" above the base of the pot.
--Timer is shut off when the water temperature >= 212°.
--Stove and gas cylinder are weighed for the "end weight".
--Stove and pot are cooled to room temperature prior to next test.
--Stove and gas cylinder are weighed before each new test, although you'll notice the weights remain consistant with previous test conclusions.
Grams per Second (GpS) is the amount of fuel burned per second to reach 212°
1 full turn of the valve. Flame is very high, very loud, and a lot of heat rolling up and away from the outside of the pot.
Start weight: 23.10oz / 655g
End weight: 22.75oz / 645g
Time to Boil: 2:19.93 (min:sec)
Fuel Consumed: 0.35oz / 10g
Grams per Second: 0.071464
1/2 turn of the valve. Flame is high, very loud, and a good amount of heat rolling up and away from the outside of the pot
Start weight: 24.06oz / 682g
End weight: 23.74oz / 673g
Time to Boil: 2:00.38 (min:sec)
Fuel Consumed: 0.32oz / 9g
Grams per Second: 0.074763
1/4 turn of the valve. Flame is medium-high, loud, and not too much heat escaping away from the outside of the pot.
Start weight: 23.74oz / 673g
End weight: 23.42oz / 664g
Time to Boil: 2:40.90 (min:sec)
Fuel Consumed: 0.32oz / 9g
Grams per Second: 0.055935
1/8 turn of the valve. Flame is medium-low, "quiet", and very little heat escaping away.
Start weight: 23.42oz / 664g
End weight: 23.10oz / 655g
Time to Boil: 9:21.47 (yes, 9+ minutes)
Fuel Consumed: 0.32oz / 9g
Grams per Second: 0.016029
Note: It took FOREVER to get the water to boil, and in fact it did NOT boil. At 210° the water temp stablized (this near the 8.5 minute mark). I had to open the valve, a little at a time, until I was at 1/4 open (stove became louder (torch-like) at this point). Then the water finally hit 212°.
1/4 turn: the point where the flame starts to "roar", audiably, seems the sweet spot. Enough heat to actually boil water, and the efficiency is much better (0.055935 GpS) than at more opened valve settings (.07+ GpS). The time to boil is well within reason too.
1/2 turn: is the sweet spot if you can't spare a few more seconds to get a boil going. Doubting I'll ever use it! (although at altitude things will most likely change)
Warmly Regarded, literally
1/8 turn: Stove is the most efficient, GpS-wise, at a low flame. Extremely efficient for long duration warming. Won't quite boil water though, but if you have a book to read it'll get close! While I didn't test lower than 1/8th turn, I'm guessing even a tiny warming flame would be extremely efficient, GpS-wise.
1 turn: pointless in my opinion, it is slightly more efficient than 1/2 turn, but a TON of heat rolls up outside the pot. I had to put on a kitchen mitt to hold the digital thermometer over the pot. I also needed the kitchen mitt to grab the pot's handles at the end of the test. I don't carry a mitt in my backpack. :p
A wider pot might help with the escaping heat. The 1.2L pot I used is the largest that I personally use/have, and is 5" in diameter. However, it's quite possible that a wider pot would change how effective a more opened up valve would be -- especially with all the heat that escaped during my experiment.
I have a BRS-3000T stove as a back up. This little ultra-light is just 25g (yes, the manufacturer's stated weight is spot on). 27g with the little carry bag it comes with. It's tiny, but I'll pack it, along with my main stove, as a spare or secondary stove. I ran a quick test on it, rough summary:
Flame is too wide and wraps up around the outside of the pot (again, 5" diameter pot). I didn't continue to test at 1/2 turn due to not wanting to handle glowing hot pot handles.
1/4 turn. Blue flame just barely extends along the base of the pot to outside edge of the pot.
Start weight: 21.02oz / 596g
End weight: 20.71oz / 587g
Time to Boil: 3:24.65 (min:sec)
Fuel Consumed: 0.31oz / 9g
GpS of 0.043978
For a ~$15 stove, this thing kicks ass. LIGHT, unbelievably light. TINY, which is very nice for stuffing away, however the width and height of the legs suffer from being so compact, making pots tippy plus pots sit a bit low on the flame. Effcient! Sure, a bit slower to boil, but it is efficient. I HIGHLY recommend this stove, if only as a spare, but it would do nicely as your main stove. Feet are small, pot tipping over is a concern. Valve silently leaks fuel when "off". A little more force in shutting off the valve seemed to work, could be just that it's new and the valve isn't fully seating. I'll have to exercise it while loafing and then see if it seals up better.
Finally, I should add that ALL tests, with both the MSR and BSR stoves, used roughly the same amount of fuel to boil the water (about 9-10 grams of fuel). However the efficiency would come more into play when you keep the heat applied after reaching the boiling point. At 1/4 turn (on both stoves), you'd do much better on fuel used over a longer duration. Even better if you turn down the flame once boiling is reached.
How many pots of water can I boil with this can of gas?
The Fuel Consumed value makes estimating (guesstimating!) how many times you can boil water from a can of fuel pretty simple. Using the Net Weight of the fuel canister, and using "10" Fuel Consumed as the "standard" makes the math easy. For example, my 16oz JetBoil fuel can's Net Weight is 450g. 450/10 = 45.0, so around 45 pots of boiling water. An 8oz MSR canister is 227g, thus 22.7 pots of boiling water.
On average, how many minutes will this can of gas run?
Excluding the BSR, the average GpS for the MSR is 0.054548. Thus CanisterNetWeight / 0.054548 = seconds
450g canister: 450/0.054548 = 8,249.653 sec / 60 = 137.494 min / 60 = 2.292 hours
227g canister: 227/0.054548 = 4,161.491 sec / 60 = 69.358 min / 60 = 1.156 hours
Note: this is the run time to achieve boiling pots of water
Another way to look at it, min/max run time.
Least efficient was at 1/2 turn. 450/0.074763 = 6,019.020104 sec / 60 = 100.317 min / 60 = 1.672 hours
Most efficient was at 1/8 turn. 450/0.016029 = 28,074.116 sec / 60 = 467.902 min / 60 = 7.798 hours
So that can will last somewhere from ~1.5 hours to ~7.75 hours of continuous burning.
Note: this is just a "run run run" result. You might be boiling water, you might be slow cooking a pot roast, or you might be heating your tent (eep!) all night long.
Another quickie test, this time using MSR's Reactor stove. Holy cow this stove boils fast. I used its included 1.7L pot, but boiled just 16oz of water like in the previous tests. However, with this stove I did use the lid, as it's integral to the design of the stove/pot. This is my finding of using just 1/4 turn on the flame. Timer started at flame ignition, pot (w/ water in it and lid already secured) was placed on the stove when the grating glowed red. Timer stopped at >= 212°
Start Weight: 26.00oz / 737g
End Weight: 25.71oz / 729g
Time to Boil: 1:30.78 (min:sec)
Fuel Consumed: 0.29oz / 8g
GpS of 0.088125
Fuel consumption wise, it's better than the MSR and BSR for boiling 16oz of water. However, the GpS is the worst of the bunch. You would want to turn this off immediately, as it is not as efficient over time (ie: slow/continuously heating food).
Conclusion: You'll save fuel with the Reactor -- if all you're doing is boiling water and you quickly extinquish the stove upon reaching a boil. If you're doing longer duration heating: you will burn more fuel with the Reactor than you would with the MSR and BSR stoves.