[Stoves] Energy efficiency value

[Crispin Pemberton-Pigott]

Dear Frank

Efficiency is important because it is related to the consumption of fuel. If a stove is twice as efficient it will use half the fuel.

In Bishkek at the moment the stove being field tested is three times as efficient as the baseline stove. Therefore it uses 1/3 of the fuel to deliver the same amount of energy (heat).

If two stoves with the same efficiency are rated differently, that will mislead the public. If a defective method used rates ten stoves as different when in fact they are the same, ‎the method has to go, not the mis-rated stoves.

Regards
Crispin


Dear Stovers,

Why is knowing the energy efficiency so important?

If we were to take a tin metal stove and provide a controlled heat source (oxygen-acetaline) and measure the energy efficiency at different, steady powers (say 1/4th, 1/2, 3/4 and full power) using the WBT as indicator this would not likely be a straight line - I am thinking. Then take a well insulated clay stove and the four points would likely be more of a straight line but all stoves would have a different curve.

Now add a controlled fuel like propane (with no O2 source) and now you add to the variables primary air and secondary air. Then switch the test to using biomass and more variables are added.

I’m thinking without a straight (or at least predicted) curve for the four power settings regarding energy efficiency that the test is meaningless. There is no good value for a stove for energy efficiency. No reason to go all out for that value.

I’m thinking a better approach is Fuel Classification vs Heat into the Pot. I think using a single type of biomass fuel we can predict the time it takes to boil the water. Use another type of fuel and it takes a little longer - every time.  The difference is not the energy in the biomass but more the Classification we give to the biomass. (still needing development). We test success using Cecil approach to find out how well it works - but know from lab study the biomass properties so to be able to compare and predict success in different locations.

Regards

Frank








Thanks

Frank
Frank Shields
Gabilan Laboratory
Keith Day Company, Inc.
1091 Madison Lane
Salinas, CA  93907
(831) 246-0417 cell
(831) 771-0126 office
fShields at keithdaycompany.com



franke at cruzio.com




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