[Stoves] stoves and credits again

[Ronal W. Larson]

List, cc Crispin

	Crispin responds here only to my fifth response in a 10-response message I sent less than a half hour earlier (at 10:16 and 10:44 Larson time).  My guess is that we will see no other.  Pity, as this deserves a lot more attention.  


> On Sep 22, 2017, at 10:44 PM, Crispin Pemberton-Pigott <crispinpigott at outlook.com> wrote:
> 
>> >>A thorough investigation of engineering sources finds no support for rating performance on the basis of any of the energy being subtracted from the denominator, the  input energy.
> 
> >[RWL5:   What is the name and location of this “thorough investigation”?‎
> 
> ISO TC-285 WG1 ‎(Conceptual Review)
> 
> As an ANSI nominated expert you should know that already. Your buddies participated in it. 

	[RWL1”:  I guess I am slowing down - but it would’ve helped if Crispin had mentioned ISO, 285, or WG1.

	I am trying in this sequence of emails to make up for the fact that I have not been a good contributor to this important and valuable international ISO stove exercise.  I came in late - mainly because of this very topic.

	The WG1 and other reports in the 285 process are listed at https://www.iso.org/committee/4857971.html <https://www.iso.org/committee/4857971.html> 

	Their status is found at https://www.iso.org/committee/4857971/x/catalogue/ <https://www.iso.org/committee/4857971/x/catalogue/>.  The numbering there makes it clear that WG2 is further along than WG1.  WG2 came to the exact opposite conclusion from WG1 on this topic of the validity of the equation e3=e1/(1-e2).   I would be greatly surprised if Crispin didn’t know this - as I am quite sure he voted against the majority in (the almost complete?) WG2 report   I don’t believe either the WG1 or WG2 report is able to be shared - but hope someone higher up in this chain can give us more from either report.  I can’t.

	Some time back on this list, there was a discussion largely between the WG1 chair,  Dr. Tami Bond, and myself on this topic.  No conclusion was reached.  But now we have the unfortunate situation that two separate ISO groups are saying different things.  I am told that (by far) the more important document is that from WG2.  It contains the above e3 equation - without any qualification.  I have been told that the WG1 report will make essentially no difference in the Tier ranking system - which is where the equation is of importance.  

	It is probably impossible to go back and make the two reports say the same thing about this equation - but I continue on the faint hope that is possible.  The main argument that has influenced the WG1 vote is over the negative sign in the denominator - which i am strongly defending - and which prevailed in the WG2 report.  Keep tuned for that further dialog (which I believe Crispin admitted had validity as identified in my response RWL8, following Crispin’s stating: 
 “If you wish to report the fraction of energy input that reached the pot and was not contained in the residual fuel, you could use the WBT formula” .    
	
	See the rest of my response RWL8 for why Crispin’s admission is so important.  As usual,  Crispin here avoids discussing the main topic of this thread.  Or maybe he will kindly respond to the rest of my 10:16  response to him (for the benefit of edifying this list on what is going on in the ISO process).


> 
> As for your favorite formula, the fact that numbers can be placed one upon another does not make the result of the calculation a valid fuel consumption metric. 

	[RWL2”:  It does make a difference when it appears in the WG2 report.
> 
> If the energy in char is useful, then it is a product of the processing of the fuel fed, in which case it goes in the numerator: char energy over fuel energy. 

	[RWL3”:  That has never been in dispute.
> 
> Applying your formula to char, it would be .
> Char energy over (fuel energy minus pot energy)

	[RWL4”:  This is total nonsense.  Using my nomenclature, Crispin asserts that  ex = e2/(e1+e2+ei-e1) = e2/(e2+ei).    (where ex is Crispin’s “it”)   In my “1/3” example ex = (1/3)/(2/3) = 1/2.    This says (hypothetical example only) that the char yield when not doing any other useful work  (which is e1) is  more than the real number - which would be ex = e2 = 1/3.  The beauty of making char in a stove is that one is capturing useful (e1) energy, without ANY pain on the char-making side.  Crispin has for some reason thrown in a question claiming some validity - when none should be acknowledged.  This equation is about as meaningful as saying ey = (e3)^2.  It is a number - yes - but why write it down?
	To repeat, in the WBT testing, e2 is totally independent of e1.  The converse is not true,  e1 is totally dependent on e2.  e3 makes up for that difference.

> 
> You would get a number, but it is also useless for reporting the char energy as a fraction of fuel energy fed or the char energy production efficiency. It is just a number. 

	[RWL5”:  It is much less than a number - it is false (error laden) number.  You have given zero reason for introducing “ it” = “ ex”- and gotten an obviously inaccurate number from valid WBT measurements.  Equations should be introduced for some reason, not just because there is symmetry.
> 
> No publication shows that the WBT thermal efficiency calculation is valid.

	[RWL6”:  Wrong.  The main one I am defending from WG2 uses the formula, because it is so obviously reporting on physical reality.  The denominator (1-e2) is real - it is the energy available to achieve the desired e1.  There are probably at least a hundred cites using this equation.

> Using something is not an argument for validity. Copying an error does not correct it.

	[RWL7”:  You are totally avoiding the issue of tiers.  To be able to compare all stoves fairly, the amount of char MUST be taken into account.  The present formula does that.  The only energy available for e1 purposes in a char-making stove is (1-e2).  The ONLY formula available for fairly REDUCING the char energy e2 when considering the e1 side of a stove is to calculate the ratio (energy out)/(available energy in).  You CAN’T use e3 = e1.  Saying the stove has a cooking efficiency of e1 +e2 is obvious nonsense for tier-ranking purposes.

> The WBT contains numerous conceptual errors, and using it does not constitute an argument in favor of any of them. 

	[RWL8”  I know of no conceptual errors, much less “numerous”.  Please cite some.  My guess is that you have been outvoted by a sizable majority of the WG2 members (I’ve never voted) on each one of these supposed “conceptual” errors.
> 
> The WBT under-reports the fuel consumption ‎of almost all solid fuel stoves if the ‘char-deducted' metric is used.

	[RWL9”:   Absolutely untrue.  The input fuel is carefully accounted for into two categories: useful work and char categories (and the remainder difference is inefficiency).   You are apparently here simply again saying that all char should be counted as waste in stove reports.  
	Voting in WG2 shows Crispin was in a minority - again all related to Tiers - which I believe to have been very helpful in advancing stove progress.

> In those few cases where there is no char produced the fuel consumption metric is correct, but not the specific fuel consumption because the fuel mass is divided by the mass of remaining water, not the mass used in the test. 

	[RWL10”:   I don’t know whether this is an important issue - but it would be simple to calculate both ways.  If all tests are done the same way, it doesn’t seem likely to influence anything important about tiers.
> 
> No comparative or absolute performance ‎rating for a stove should be trusted if it was made using the WBT.

	[RWL11”:  In my opinion, you have failed to make any convincing argument on trust in the WBT - as the WG2 group that I  trust seems to have outvoted you on all of these issues.  On the issue of most importance to me - the e3 = e1/(1-e2) issue, I continue to believe (and the WG2 group has endorsed) that formula.  You have given no better alternative for handling char - other than to say it should be treated as waste when made in a cook stove.  Frankly, that seems idiotic.

> It rarely reports the actual performance, even on those metrics which are valid. (None of the low power metrics are valid.)

	[RWL11”:  Where should people go to see your argument on this topic?   Are we talking 3rd decimal point in these metrics?

Ron
> 
> ‎Regards 
> Crispin 
> 
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