Originally Posted by
MuddyWaters
Maybe.
If you have blended fuel, you disproportionately lose the more volatile species first. Which leaves you with weaker burning cannister at same temperature due to lower vapor pressure.
If you are smart enough to adjust flame as cannister depletes, you will probably never notice at warm ambient temps. Near freezing you may practically cease to work, so yeah..it might have an effect
At low cannister level the vaporization rate cools the small remaining mass more as well, slowing heat output significantly.
Now the truth...only something like around 1/2 of energy goes into water...rest is lost...so you can affect some things marginally, via heat exchangers and insulation and windbreak design.
Say you take 7 g fuel to heat 16 oz water 40-212F. Roughly 172 btu. The 7 g fuel had closer to 300 btu for heat of combustion. Much is lost by heating excess air, which lowers your flame temp too.
My little cannister will basically boil 2 cups rt water on 5.8 g fuel using tight windscreen around pot bottom, and 7-8 min heating time. Only slightly more than the 4.25 g a jetboil does with its heat exchanger and insulated pot. Just much slower. Im 56% efficient. The jetboil is 77%. Normal cannister run high rate without windscreen is more like 38% in my experience (8.5g). But a pot that is wider with more bottom area, may be more efficient than my small one on high.