[Stoves] Question regarding calculations

[Frank Shields]

Dear Stovers,
If I understand this graph it is fascinating. 
It takes less energy to maintain a temperature at 40c than it does to maintain a temperature of 15C or 75C. 

Our body temperature requires the least amount of energy to be maintained at 37c

Compost sent to curing piles cools and hovers around 40c with composers thinking it is still very active but it takes less microbial activity to maintain 40c than if it were to maintain at 25c.

Anaerobic digesters natural go to 36C where it requires the least microbial activity to maintain that temperature.



Whatever it is about water molecule that lowers the input of energy required to maintain a temperature of 40c seems well used by our natural environment. 


Regards

Frank (sitting under the Bodhi Tree)

The thermal capacity of water is not a constant. At 1 atmosphere pressure a good correlation is 

https://syeilendrapramuditya.wordpress.com/2011/08/20/water-thermodynamic-properties/ <https://syeilendrapramuditya.wordpress.com/2011/08/20/water-thermodynamic-properties/>
which, of course, you have to integrate over the delta T to get the effective value. 

The thermal capacity is less sensitive to pressure over the range you are concerned about – the change to 1500m altitude will affect the 3rd decimal place in value calculated at constant pressure.
 
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