[Stoves] Question regarding calculations

[Frank Shields]

Dear Stovers
Re-read my question and now see the problem. I ment to say ' keep water at 80c' and does that require the same energy at sea level as it does at 1500 meters? Sorry. Not 'boiling'!

Maintain a boil at 1500 meters takes less energy than boil at sea level I think.

And ask one question leads to ten more. 

Thanks
Frank



Sent from my iPhone

> On Oct 4, 2015, at 2:18 PM, ajheggie at gmail.com wrote:
> 
> [Default] On Tue, 29 Sep 2015 20:17:29 -0700,Frank Shields
> <franke at cruzio.com> wrote:
> 
>> Greetings Stovers, 
>> 
>> Wanting to know if it takes less energy to keep water boiling at 80 deg. C at 1500 meters than at sea level?
> 
> Frank I've waited before ploughing in because I couldn't understand
> the reasoning behind your question.
> 
> The thing is at 1500 metres above sea level the pressure is still 96%
> of pressure at sea level, so to boil water you have to raise the
> temperature of water until it's vapour pressure equals the ambient air
> pressure, and that is at 98.6C
>> 
>> Also; It take 4.186 j/g/deg.C to raise water from 20c to 80c at sea level. But is it the same at 1500 meters? or is it less than 4.186?
> 
>> From Prof Lloyd's post the specific heat of water varies with
> temperature and is probably thus not variable with pressure.
> 
> So my view would be to keep water at 80C at 1500 metres asl in a
> saucepan with tight fitting lid, so no vapour escapes would be the
> same power as at the same ambient temperature as at sea level.
> 
> AJH
> 
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