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Dennis Park
(dpark) - MLife

Locale: San Francisco Bay Area
chimney vs. pressure alcohol stoves on 06/19/2009 00:31:07 MDT Print View

After reading about alcohol stoves, I get the sense that pressure stoves are more efficient/hotter than chimney designs. Is this true? If so, why is that? I can only conceptualize that multiple little flames generate more heat than a single big flame.

Rog Tallbloke
(tallbloke) - F

Locale: DON'T LOOK DOWN!!
Re: chimney vs. pressure alcohol stoves on 06/19/2009 03:12:58 MDT Print View

Amount of heat produced by a stove and efficiency tend to be negatively correlated. The quicker you wan to boil your water, the more fuel the stove will use.

Alcohol stoves are much lighter than pressure stoves, but the fuel has a lower calorific value, so you carry more fuel weigh for the same amount of heat produced.

Alcohol for shorthaul trips up to 5 days, butane for longer trips seems to be the consensus of opinion, disregarding other issues like fuel availability and seasonal temperature.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: chimney vs. pressure alcohol stoves on 06/19/2009 04:32:35 MDT Print View

I am not sure what you mean by either of the terms you have used - pressure and chimney. Please explain?

Cheers

Tim Marshall
(MarshLaw303) - MLife

Locale: Minnesota
Re: Re: chimney vs. pressure alcohol stoves on 06/19/2009 07:42:48 MDT Print View

http://zenstoves.net/Stoves.htm

This will help explain the terms used.

I like chimney stoves as they are easier to make and fill and they won't blow apart no matter what (nice plus)

-Tim

Frank Deland
(rambler) - M

Locale: On the AT in VA
stoves on 06/19/2009 11:02:48 MDT Print View

Here is what Rog was referring to.

http://thru-hiker.com/articles/stoveweight_vs_time_14days.php

10 days worth of alcohol weigh about the same as the canisters needed for the same amount of time. (boiling 2-3 cups of water for dinner) The weight savings would be in the weight of the stoves.

For chimney vs. Pressurized alcohol stoves, I agree with Tim, the cat can stoves are about the easiest to make because they also include the pot stand in the can itself.

Other factors would be the effectiveness of the wind screen, height of the pot above the flame. I have not heard comments about the effectiveness of the different stoves, so I would not think there is much difference. Personally I am not one to be concerned if it takes three minutes or five minutes to get the water boiling. I am more interested in how long it takes for the boiling water to cool down, so that I can eat dinner!

BTW Since you are making a alcohol stove, you might as well keep going and make an easy-to-make wood stove which will also host your alcohol stove.

tarilgear.net

Edited by rambler on 06/19/2009 11:04:55 MDT.

Kevin Beeden
(captain_paranoia) - F

Locale: UK
some confusion? on 06/22/2009 12:57:48 MDT Print View

> Alcohol stoves are much lighter than pressure stoves, but the fuel has a lower calorific value

I supect Dennis is asking only about alcohol stoves

- chimney (e.g. Cat stove, or the one supplied with the Caldera Cone
- low pressure (e.g. Trangia-style open burner)
- medium pressure closed burner(Penny stove)
- high pressure closed burner (e.g. one of the ones with a screw to seal the fill port).

My experience with tests seems to suggest that the chimney stove is relatively efficient.

> Amount of heat produced by a stove and efficiency tend to be negatively correlated.

Pretty much agree with that, although it depends on the entire cooking setup of burner, pan and windshield. A fast-burning stove is only inefficient if the pan and windshield can't deliver that high heat to the pan contents.