[Stoves] Test methods for cook stoves

[Frank Shields]

Dear Crispin,




On Mar 17, 2015, at 2:57 PM, Crispin Pemberton-Pigott <crispinpigott at outlook.com> wrote:

> Dear Frank
>  
> 1) 
> We only need biomass/task and time/task as final measurements. The energy going into the water in a WBT (for example) is no more important than determining the energy going into bacon frying or energy going into a turkey roasting. Fuel efficiency calculations are just more unnecessary variables that increase the ‘noise’ of the test and result in poor precision amongst labs. 
>  
> I disagree about the purpose of testing. Programmes that promote fuel saving stoves what the amount of fuel consumed to be reduced. If the stove does not save fuel, it is not going to be promoted. If the test (like the WBT) doesn’t report the fuel consumption, then it is not serving the purpose as required by the stove promoter.
>  

"save fuel” - based on what is already being done? or comparing one stove to another based on results of biomass/task and time/task? Biomass/task is a measure of fuel savings. 

 
> The main purpose of CDM stove funding is to reduce fuel consumption. Knowing how much energy was used doesn’t tell us that because people are making charcoal these days and that is fuel consumed but not energy released. This issue is fundamental. There is little point in providing a test metric that is not required.

Thanks - excellent point.  But the energy used is a percent of the biomass used (so the biomass can be calculated) and the char left has no benefit to the task that was done. Perhaps useful for a later task (stove selling point) - but just energy wasted as far as this first task.  
>  
> 2)
> Suppose we want to list stove testing labs around the World (thats what we want to do -right?). We have 25 that send in their money to be tested to get Qualified. We send each a like stove and like fuel for testing. We form a bell curve of the results (biomass/task and time/task). Five are outliers so leaving 20 Qualified labs. 
>  
> That is how to test labs not how to test stoves. The lab is supposed to ‘get a result’. But that result is making the stove ‘do something’. If that ‘something’ is a task no one on planet Earth does, then the ‘performance rating’ of the stove is meaningless. Performing another task with another fuel would have produced a different result – sometimes very different. If a stove is designed to be great for simmering there is no point testing it as a fish dryer.
>  
Agree
> Example A:
>  
> Example B:
>  
> I understand about how to test labs. We are trying to test stoves. Let’s assume you have 13 qualified labs. Now what?
>  
> Testing stoves in a manner that does not reflect use is basically pointless because you don’t learn anything about how they will behave in use.
These 13 labs that have shown they can start the fire, keep the stove going and do a simple task as well as the other labs and get the same results (biomass and time per task), is good to go. They can now be provided a stove to test and the fuel (or fuel requirements) to be used and they complete a task recording biomass and time needed. The biomass and time needed are comparable to other labs conducting the same test on the same stove. The emissions can be tested at the same time if the lab has proven they have the equipment and can use it properly.  


> >Until we do the above - We Go Nowhere!
>  
> I agree with that!  J
>  
> >…All this testing means nothing (except research) until we have enough control such that all labs get the same results and the results are meaningful to the group being marketed (using their available fuel and tested using their task(s)). 
>  
> Again, let’s assume the labs can get reasonably similar results for a stove and a burn cycle and a fuel. Now, how do we rate a stove that is going to be used to make maize porridge in Lusaka.  Should we use a cooking cycle in the lab that represents making maize porridge? Or not? How do we select a good stove for Lusaka?
>  
The same question can be applied to emissions. I suspect the emissions released will be different depending on the pot shape and contents (water filled or hot plate) it is heating. Different in both chemistry and particulates.  (?)  

> Rating a stove on a maize porridge cycle burning dry square Douglas Fir is not going to tell us much about Lusaka because everyone there burns charcoal. You get my point? Testing out of context gives answers out of context.
>  
> You could provide really good analogies for this. What fertilizer should be used to grow Beans? You cannot answer that question until you know something about beans and the soil in the field. You don’t just ‘pick the best fertilizer’.  The field, and the bean variety, and the rainfall, and the insolation are all part of the context.  Every farm is different.  You assess fertilizers in a context. So must it also be with stoves.
>  
> No more ‘universal test cycles’. You can have a universal testing framework and universal protocol with approved calculations, but the burn cycle is local, or selected from a set of standard burn cycles which have been created to represent certain common cooking patterns. Once a fuel and moisture spec is added, that testing context becomes unique.  No emissions or performance numbers, even for heat transfer, are relevant to other contexts. Stoves should be optimized for the tasks they should perform.
>  
> Any qualified lab (as you describe) should be able to perform the same test cycle with the same fuel and pot (etc) and get a similar result. That in no way means that all stoves should be tested using the same cycle, pot and fuel. You could do it but the result would not be useful.
Agree   Agree - -but   
How can a person with stove designed in Minnesota have their stove tested for use in Lusaka? and compared to others marketing stoves there? and then want to sell stoves in Koluha, India? Traveling to different countries and testing with locals and their fuels will get a little expensive! and there may be a lot of high quality stoves are not in the running because of cost and requirements. : (      So we get standards for ‘like fuels’ to be used in testing. And define the task to select the ‘cooking utinsal’ that is to be used on site.  

Thanks

Frank





>  
> Regards
> Crispin
>  
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