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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:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>David---<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><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>This is an issue we’ve tried to resolve as well as it doesn’t appear to be explicitly addressed in 90.1. To complicate issues, it is hard to find this data from many manufacturers. As a result we have applied standard practice to the baseline model which says that a typical heat pump can operate to about 5</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>°</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>F (-15</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>°</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>C) before its COP is equivalent to just electric resistance heating. So if you are using eQUEST, you can set the Maximum HP Supp Temp to 40</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>°</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>F and the Minimum HP Temp to 5</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>°</span><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>F and the heat pump will ramp down between the two set points. There is a pretty informative article provided by Natural Resources Canada that details out some of these parameters (</span><a href="http://oee.nrcan.gc.ca/publications/infosource/pub/home/heating-heat-pump/asheatpumps.cfm">http://oee.nrcan.gc.ca/publications/infosource/pub/home/heating-heat-pump/asheatpumps.cfm</a>)<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D'>Regards,<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><p class=MsoNormal><b><span style='font-size:7.5pt;font-family:"Arial","sans-serif";color:#DB824A'>Andrew Craig </span></b><b><span style='font-size:6.0pt;font-family:"Arial","sans-serif";color:#DB824A'>EIT, LEED AP<br></span></b><span style='font-size:7.5pt;font-family:"Arial","sans-serif";color:#4D4D4D'>Mech Proj Designer<br></span><span style='font-size:2.0pt;font-family:"Arial","sans-serif";color:#4D4D4D'><br></span><b><span style='font-size:7.5pt;font-family:"Arial","sans-serif";color:#DB824A'>INTERFACE ENGINEERING<br>email </span></b><span style='font-size:7.5pt;font-family:"Arial","sans-serif";color:#4D4D4D'><a href="mailto:andrewc@interfaceeng.com"><span style='color:#4D4D4D;text-decoration:none'>andrewc@interfaceeng.com</span></a><br></span><b><span style='font-size:7.5pt;font-family:"Arial","sans-serif";color:#DB824A'>direct </span></b><span style='font-size:7.5pt;font-family:"Arial","sans-serif";color:#4D4D4D'>503.382.2696<br></span><span style='font-size:2.0pt;font-family:"Arial","sans-serif";color:#4D4D4D'><br></span><b><span style='font-size:7.5pt;font-family:"Arial","sans-serif";color:#DB824A'><a href="http://www.interfaceeng.com/"><span style='color:#DB824A'>www.interfaceeng.com</span></a><br></span></b><span style='font-size:2.0pt;font-family:"Arial","sans-serif";color:#4D4D4D'><br><br><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 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"'> bldg-sim-bounces@lists.onebuilding.org [mailto:bldg-sim-bounces@lists.onebuilding.org] <b>On Behalf Of </b>Zhen Tian<br><b>Sent:</b> Wednesday, January 05, 2011 3:00 PM<br><b>To:</b> 'Building Simulation - post'<br><b>Subject:</b> [Bldg-sim] LEED modeling for Appendix G-Air to Air heat pump withauxiliary heat<o:p></o:p></span></p></div><p class=MsoNormal><o:p> </o:p></p><table class=MsoNormalTable border=0 cellspacing=0 cellpadding=0><tr><td valign=top style='padding:0in 0in 0in 0in'><p class=MsoNormal>Hello All,<br><br>I have a LEED project modeling for the baseline of air-to-air heat pump system with electrical auxiliary heat. In G3.1.3.1 of ASHRAE 90.1-2007, the requirement is " <span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:black'>The systems are controlled with multistage space thermostats and an outdoor air thermostat activate electric heat only on the last thermostat stage and the outdoor air temperature is 40 <sup>o</sup>F and below.".<br><br>In my DOE2.2 model, the electrical heat is activated only when the outdoor air temperature is below 40 <sup>o</sup>F. But meanwhile is the air-to-air heat pump system still running or turned off? From the description above we cannot find proof whether it is still running or shut off. I looked up other materials such as the ASHRARE 90.1-2007 user manual or Advanced Energy Modeling For LEED Technical Manual and none mentioned the heat pump is continuously run when the outdoor air temperature is below 40 F. <br><br>Does anyone have any good insight on this? Thanks for you help.<br><br>Regards,<br><br>David </span><o:p></o:p></p></td></tr></table><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Calibri","sans-serif"'><o:p> </o:p></span></p></div></body></html>