[Stoves] Global Alliance for Clean Cooking Stove catalog

Mon Jun 9 14:34:46 CDT 2014

Dear Teddy

Well as a manufacturer <http://www.newdawnengineering.com/>  of 30 years as of last month, I certainly hear you on the materials score. I have been active in SME assistance for ages and getting access to raw materials at the same price as large factories is a critical part of becoming successful.

Kenyan steel is largely from India and is Inches sized for that reason. Really old fashioned. Are you getting any wire from the Czech Rep? Metal sheets from Italy? South African sheets and plates? Who is active in the region? The landscape changes slowly, but it changes.

You have given me an idea which used to be a look-up table in my office. We need an international version. Something else that is worth collecting is where to buy the right tools. Hand making stoves is often seen as a sort of limited version of reality. Our company (not that I do anything there any more) specialised in making machines that were to be used without electricity, meaning hand fabrication.  Having the right jigs and fixtures and hand tools makes all the difference between being able to crank out a stove per hour and a stove per 5 minutes. The total time in labour to make a Vesto is 8 minutes. The tooling involved used one hydraulic press. Every operation was planned to take 20 seconds or less. Planning production well and having the right tools can make up for the reality of material costs in an emerging market.  People say labour is expensive but labour is expensive if it is applied incorrectly. 

Something that makes it important for have constancy in product is that, for example, the Indonesian CSI pilot project requires that drawings be submitted so that if a stove is approved, the products shipped in later using that permit are not different. This is no small matter. South Africa requires the same thing to get a paraffin stove approved for sale in that country.  People change the specs and ship in something inferior, get caught when the drawing is not matching, and the product is rejected at the border. If you want to supply 10,000 stoves and they are substantially handmade, you need the right tools and proper jigs so the performance is predictable.

Regards

Crispin

Well, the devil is certainly in the details - thank you for laying this out so well Crispin. 

On another note - does anyone know of any plans for the Alliance (or anyone else besides Google) to address the lack of reliable information linking small/medium enterprises across the developing world to quality raw-material suppliers? A specific stove makers tools and materials catalog of sorts - even it just comprised certified addresses and product lists of reliable sheet metal and allied products suppliers (ideally from 'green/ethical' manufacturers/supply chains...it would such a shame for a stove to be made from products of illegal mining operations or highly polluting factories etc.)  would, at least to me and many other manufactures in Kenya - be a huge help in reducing production costs. 

Teddy

Cookswell Jikos
www.cookswell.co.ke <http://www.cookswell.co.ke> 

www.facebook.com/CookswellJikos <http://www.facebook.com/CookswellJikos> 

www.kenyacharcoal.blogspot.com <http://www.kenyacharcoal.blogspot.com> 

Mobile: +254 700 380 009 

Mobile: +254 700 905 913

P.O. Box 1433, Nairobi 00606, Kenya

  <https://lh5.googleusercontent.com/-mFnK50B4oS8/UUrgJle8z9I/AAAAAAAAB_o/OUjLd7wrKPg/s133/Cookswell+Logo.PNG> 

Save trees - think twice before printing.

On Fri, Jun 6, 2014 at 12:07 AM, Crispin Pemberton-Pigott <crispinpigott at outlook.com <mailto:crispinpigott at outlook.com> > wrote:

Dear Erin

Thanks for that link

http://catalog.cleancookstoves.org/#/stoves 

Regarding the emissions and metrics: It will be in interest to the stove community know that some consideration has been going on behind the scenes and on this list for years about what metrics are the most useful to report. There is not yet full agreement so I am bringing it forward again as something that needs work:

This is the list at the bottom for an Oorja Stove from India

Note that the emissions of PM are given as BC (black carbon) per kg burned, PM2.5 per kg of fuel burned and PM2.5 per minute.

I find this PM mass per kg burned almost uniquely American in that the EPA started off giving emissions per unit of mass and everyone copied that, at least among the early adopters. Not sure really where it started, but it is misleading as we have discussed several tiems before.

The problem is that the numbers are not useful directly unless you know what the kg of fuel was, and a comparison cannot be made with other fuels unless a conversion is made first to get the heat content normalized, and then to incorporate the system efficiency (not the heat transfer efficiency).  Because the system efficiency is not reported, it means from the above numbers, one cannot get the most practical metric from the list (because some info is missing).

A stove is used to cook, and people burn the fuel until the cooking is done. If the heat transfer efficiency is poor or the stove wastes a lot of fuel (making leftovers that are not useful in the next fire, for example) then the amount of PM emitted will be high ‘per useful MJ’ but not necessarily ‘per kg’. In short, one cannot tell if the total emitted to cook something is higher or lower than for another stove.

If a stove a) burns all the fuel put in it, b) has a high heat transfer efficiency and c) has a lower mass of PM emitted per useful MJ of heat then we have something that can be compared across the board: any stove, any fuel, anyplace. All you need to do is plug in your burn cycle.

So if you can report the mass of BC and PM2.5 emitted per useful MJ delivered to the pot, you have the analogy for emissions smoke per unit or per task of ‘cooking’.  

The most useful metric is PM2.5 mass per MJ(net) accumulated in the pot.

I say ‘net’ because heat transferred that is lost from the sides is not accumulated. If you were perfectly simmering, all heat gained by the pot would be lost from the sides in which case there would no net gain (no change of enthalpy). When ‘boiling’ this same process is going on it is just swamped by the gain of heat in the water and food, but it is still there. 

It is the net heat gained by the pot that is useful cooking energy. As people will, say, boil 5 litres of water, it takes about 1.8 MJ each time in the pot. How much PM is emitted per kg is not nearly as important as the emissions per MJ. You get my drift?

Thus when comparing the emissions we are interested in two numbers for PM: The mass emitted per MJ delivered, and the rate of emissions into the room (which is the last number on that list). Depending on the kitchen architecture, that rate sets the smoke concentration in the room if it is an open fire type device (no chimney).

Apart from checking the validity of the metrics, we should investigate the underlying assumptions about how the number will be used to make comparisons. 

Regards

Crispin

_______________________________________________
Stoves mailing list

to Send a Message to the list, use the email address
stoves at lists.bioenergylists.org <mailto:stoves at lists.bioenergylists.org> 

to UNSUBSCRIBE or Change your List Settings use the web page
http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org

for more Biomass Cooking Stoves,  News and Information see our web site:
http://stoves.bioenergylists.org/

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20140609/0418a4dc/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image001.jpg
Type: image/jpeg
Size: 8864 bytes
Desc: not available
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20140609/0418a4dc/attachment.jpg>