<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=utf-8"><meta name=Generator content="Microsoft Word 15 (filtered medium)"><style><!--
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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal>> <b>On Behalf Of </b>Adrian Tymes via extropy-chat<br><br><o:p></o:p></p></div><div><div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>>…We took 3 furnace filters - the large rectangular panels that are at least a meter tall - and made a triangular prism box out of them plus some cardboard, and a fan at one end (the cardboard cut around the fan), sealed it all together with lots of duct tape, and let the fan run so as to blow air through the filters. Not 24 hours later, the filters were already dark toward one end, suggesting they are indeed scrubbing a lot of particles…. spike <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Adrian you are fun guy to have on a mailing list. I just ordered a box of furnace filters.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>spike<o:p></o:p></p></div></div></div></div></body></html>