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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:10.0pt;color:black'>Paul,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;color:black'>I interpret as the allowable Standby Loss is:<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;color:black'>80%Et (Q/800+110 SqRt V)<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;color:black'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;color:black'>Footnote a indicates SL is maximum BTU/h based on 70 degree temp difference between stored water and ambient requirements.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;color:black'>Mark</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> equest-users-bounces@lists.onebuilding.org [mailto:equest-users-bounces@lists.onebuilding.org] <b>On Behalf Of </b>Paul Diglio<br><b>Sent:</b> Tuesday, October 04, 2011 7:37 AM<br><b>To:</b> equest-users@lists.onebuilding.org<br><b>Subject:</b> [Equest-users] 90.1-2007 Table 7.8 Water Heater Efficiencies<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal><span style='font-size:10.0pt;color:black'>Could anyone help me understand the calculation for the minimum efficiency of gas storage water heaters per the table above?<br><br>The calculation is 80%Et (Q/800+110 SqRt V) SL, Btuh.<br><br>I understand that Q is the nameplate input rate in Btuh and V is the volume.<br><br>Do I use the volume of the whole system, the storage tank only or the recovery rate volume?<br><br>I understand SL is the standby loss. Does SL, Btuh mean multiply the equation in parenthesis by the standby loss in btu's per hour?<br><br>Thanks for the help,<br><br>Paul Diglio<o:p></o:p></span></p></div></div></div></body></html>