<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class="">Dear Crispin,</div><div class=""><br class=""></div><div class="">Before I sit quietly I would just like to ask one question regarding this following section:</div><div class=""><br class=""></div><div class="">Where does energy need to come in?</div><div class=""><br class=""></div><div class="">We gather some wood and we cook a meal and sit down to a bowl of rice, some meat grilled over char and a cup of tea. How much wood did we use from the forest to boil water, cook some rice, and use the char left to cook the meat. </div><div class=""><br class=""></div><div class="">The more fuel the less efficient. </div><div class="">The less fuel the more efficient.</div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">All based on weight of dry fuel per tasks completed. </div><div class=""><br class=""></div><div class="">Regards</div><div class=""><br class=""></div><div class="">Frank</div><div class=""><br class=""></div><div class="">Frank Shields</div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><br class=""><div><blockquote type="cite" class=""><div class="">On Nov 28, 2015, at 1:33 PM, Crispin Pemberton-Pigott <<a href="mailto:crispinpigott@outlook.com" class="">crispinpigott@outlook.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div style="font-family: Helvetica; font-size: 18px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span style="color: rgb(31, 73, 125);" class="">></span>A ) (Fuel Efficiency%) = ((task 1 + Task 2) / (dry wt biomass fuel) ) X 100<o:p class=""></o:p></div></div><div style="font-family: Helvetica; font-size: 18px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class="">This is the dry fuel<span class="Apple-converted-space"> </span><u class="">taken from the forest</u><span class="Apple-converted-space"> </span>required to complete task 1 and task 2. Doesn’t matter the energy or time it takes to do it. As long as the stove(s) can complete the task(s) the stove(s) can be tested. There must be a very sharp endpoint telling when the task(s) are completed. Excess fuel left in the stove is wasted. <o:p class=""></o:p></div></div><div style="font-family: Helvetica; font-size: 18px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span style="color: rgb(31, 73, 125);" class=""><o:p class=""> </o:p></span></div><div style="margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: 'Times New Roman', serif;" class=""><span style="font-size: 11pt; font-family: Calibri, sans-serif; color: rgb(31, 73, 125);" class="">This takes a mass-based approach and it has little use for stove performance rating. The problem is there is more than one fuel and as they have different energy contents, comparing the mass consumed doesn’t tell us precisely the performance. It has to be done on an energy basis because the work done is based on energy (we have to use something). Similarly emissions per kg of fuel burned are not ideal for measuring stove performance. They are useful for air-shed modelling but are usually misconstrued because a fuel does not by itself, have ‘characteristic emissions’.</span></div></div></div></blockquote></div><br class=""></body></html>