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</o:shapelayout></xml><![endif]--></head><body lang=EN-CA link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>Dear Teddy and Kevin<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>The most common ‘old’ method was to have an opening on the stove top (rings) which were removed to expose the pot bottom to the fire for high power cooking and to put the ring or disk back in order to turn it down. Placing a metal plate on top of a metal cooking surface between the pot and stove accomplishes the same thing, giving ‘even heat’ (which is a good point to highlight). <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>Clearly this lowers the fuel efficiency of cooking, but it may not matter if a) the stove is really fuel-efficient, b) if the fuel is easily available and reducing consumption is not a priority or c) if there is some other benefit such as space heating that is desired at the same time. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>The last case prevails in Mongolia during the 9-month heating season. The cooking efficiency (which ranges from 15-25%) is barely considered as the main task is heating. Some stoves are not used for cooking at all.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>In some areas of Indonesia the main daily cooking task is evaporating water to make palm sugar so that continues at high power while the cooking is done on secondary or tertiary pots. Those additional pots are used together with rings and plates to control the power reaching them. Some stoves have a moveable baffle that directs the hot gases upwards, either more or less.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>The point is of course, to control the cooking power to suit the meal being prepared. It is important that stove designers are aware that there is no specific requirement to control the fire itself ‘enough to reduce the cooking power over the range of 4:1’ (for example) just a requirement that such a reduction can be engineered by the cook using the facilities of the stove.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>Regards<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>Crispin<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>Dear Kevin, <o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Thank you very much for this, I have been thinking about that quite alot in regards how people in Kenya (and E.A) cook ugali (a polenta maize flour type of food). It starts out liquid but ends up a solid - how much will the size (diameter) of the source contribute to cold/hot spots during this conversion? Is a graduated turn down function or a simple high/low better for controlling this? <o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Thanks, <o:p></o:p></p></div><div><p class=MsoNormal><br>Teddy <o:p></o:p></p></div></div><div><p class=MsoNormal><br clear=all><o:p></o:p></p><div><div><div><p class=MsoNormal><b>Cookswell Jikos</b><br><br><o:p></o:p></p></div></div></div><p class=MsoNormal><o:p> </o:p></p></div></div></body></html>