<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=us-ascii"><meta name=Generator content="Microsoft Word 12 (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>Hi,<o:p></o:p></p><p class=MsoNormal>Does anyone have an Excel-friendly equation they would be willing to share that can convert Tdb and RH into Twb? We have metered data giving us Tdb, RH, and Tdp, but we need to know wetbulb. We usually solve this problem with an Excel psychrometric add-in, but we need to distribute this spreadsheet to a client and cannot distribute the add-in at the same time.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>We’ve tried a couple of multivariable regressions on the data, but because it is nonlinear, it is not proving to be that straightforward. Next stop might be a two-way lookup table, but that is kind of cumbersome and was hoping to avoid it.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Any help much appreciated.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Sincerely,<br>Alec Stevens<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>DMI<br>35 Walnut Street, Wellesley, MA 02481<br>p: 781 431 1100 x11 f:781 431 1109<br>e: astevens@dmiinc.com<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>