I still kinda think that if you burn the same amount of fuel (propane, gasoline, wood) yer gonna get the same amount of heat as the chemical reaction hasn't changed. Given the combustion we're talking about is in open air, I don't think that there will be "incomplete" combustion to any great extent due to a lack of available oxygen (at the altitudes we're likely to be camping). If your propane or gasoline stove is pumping out the same amount of fuel, there will be more than enough oxygen in the air to provide for complete combustion, and yer gonna get the same amount of heat. I think.
Here is a web site that makes an interesting point that the heated air, due to its being less dense, has less capacity to carry heat. I kinda think that the transfer of heat to the cooking vessel by the thinner air might be more of a factor than the supposition that the flames are "cooler" due to less oxygen being available for combustion. Again, within the limits of the altitudes folks are actually camping at.
The "Rocket Scientist" said that you lose about 3% of heating capacity in a typical heater per 1000 feet in altitude (although the article cited below says 4%, who ya gonna trust). It might be that the regulator used to regulate the fuel gas might be producing a gauge pressure (pressure compared to outside pressure) versus an absolute pressure (meaning if the outside pressure decreases the regulator puts out the same pressure when compared to the outside atmospheric pressure but when the outside pressure drops the absolute pressure of the fuel gas also drops). If the pressure of the fuel gas is lower, less gas will flow through the fixed orifice, and as less fuel is being burned, less heat will be produced.
http://www.achrnews.com/articles/select ... tude-homes
As I stated earlier, I think that there is "more to it" than the one supposition that the flames of the fire are cooler.
Another explanation is that I'm, typically, just making it more complicated than it really is but its always fun to know the truth and learn something new.
We need some serious controlled experiments to really determine what is going on.
You'll, though, get no argument from me that it takes longer to cook foods at altitude but mostly because water can't get as hot as it can at sea level.
Cheers,
Gus
The opinions in this post are my own. My comments are directed to those that might like an alternative approach to those already espoused.There is the right way,the wrong way,the USMC way, your way, my way, and the highway.
"I'm impatient with stupidity. My people have learned to live without it." Klaatu-"The Day the Earth Stood Still"
"You can't handle the truth!"-Jack Nicholson "A Few Good Men"
"Some people spend an entire lifetime wondering if they made a difference in the world. The Marines don't have that problem"-Ronald Reagan