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When reading backpacking stove adds I often read the words fast and efficient as meaning the same thing. As mentioned in my introduction I have setup some stove testing equipment in my garage at home. I wanted to know if faster was more efficient or is it just more of the marketing spin that we are so used to.
Below are the results of some test that I did some time ago where I compared Alcohol, Petrol (White gas or Shellite) and Gas (Canister) stoves vs time to boil and to each other.
I tested a Trangia 27-1, a MSR Whistperlite and MSR Pocket Rocket all of them are considered to be classic stoves and are available in most countries of the world.
The tests where done through a range of adjustment settings from the fastest to the slowest that I could get the stoves to operate with in reason. I used a 1l Snowpeak Titanium pot 150 mm diameter with a specially made Stainless Steel lid with a hole in the middle so I could place my temperature measurement probe into the water, I used 1 liter of tap water in these tests.
All test results have been normalised, I measure the start temp of the water and stop the tests when the water reaches 95C, I weigh the fuel at start and at end, I then calculate the fuels used per 1C temp rise I then normalise to fuel used per 80C, the ambient temperature for these test was around 20C.
With the Trangia I used the simmering ring to choke the flame down to produce the slower heating rates, the fastest heating rate used was with no simmer ring.
The Whisperlite was the hardest to adjust, I did this by pumping different number of pumps into the fuel tank from a few pumps at a time to about 40 pumps and the valve was opened fully in all tests.
With the Pocket Rocket, this was simple I adjusted the heating rate by adjusting the valve from very fast to very slow, if the valve was opened too much lift off of the flame was experienced
The results show the amount of fuel used in each test in grams vs time.
Note that no matter how slow I adjusted the heating rate it used the same amount of fuel from 12 minutes to 30 minutes. 23-24 grams, Note the Trangia used nearly twice as much fuel as the correctly adjusted Pocket Rocket, this roughly is in line with heating energy contained in the different fuels.
The Whisperlite showed great improvement in efficiency 25% with slowing down the heating rate, this stove is not design to simmer and is very inefficient at the normal setting, though it has the advantage of working in very cold conditions.
The Pocket Rocket also benefited from slowing down the heating rate a 25% improvement was seen. Note as can be seen from the curve (yellow line) that using the Pocket Rocket at too high a heating rate is a waste of energy, a time of around 12 minutes seems to be the optimum and heating rate faster was a waste of fuel and slower was a waste of time. Please note the most efficient fuel/time point 12 minutes coincides with the fastest heating rate from the Trangia 12 minutes, I am not sure if this means anything though but I found it an interesting point. Upright canister stoves have problems working in cold conditions but they can still work in the cold if used correctly.
Is fast boiling, efficent boiling, I think my results speak for themselves.
I hope this information is of some help to stove users and prospective stove buyers.
Please note, I have previously shared this information on some other forums and on my blog.