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</o:shapelayout></xml><![endif]--></head><body lang=EN-CA link=blue vlink=purple><div class=WordSection1><p class=MsoPlainText><span lang=EN-US>Dear Andrew<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>></span> <span style='color:black'>My conclusion is that these industrial type woodburners have an even better performance in terms of air quality than the bald figures suggest because our cookstoves typically have PMs of PICs formed in the secondary combustion, with much higher organic carbon, and it is these that are implicated in the health problems from indoor air quality.<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>There is one essential number needed to have that conversation (about the industrial burners having better performance) and that is the absolute potential emissions from working examples of the naturally aspirated stoves (cooking or not).<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>I agree that the 'typical' cooking stove is not going to be as good, however I am inspired by the really good results that are possible with some of the new configurations so I was wondering if we can get two numbers to compare: the ash-free PM from both burners. Fans are definitely causing more fuel bed turbulence and lofting particles that might otherwise fall into the ash bin.<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>If the best non-fan (unblown?) combustors are as clean as the industrial ones, we are doing <i>really</i> well compared with 5 years ago. Big improvement!<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p><p class=MsoPlainText><span style='color:black'>Regards<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'>Crispin<o:p></o:p></span></p><p class=MsoPlainText><span style='color:black'><o:p> </o:p></span></p></div></body></html>