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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='color:#1F497D'>Hi Molly, <o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Based on what you describe, you have your eyes on all of the DCV toggles in eQUEST. One thing that you didn’t mention though was the type of system you’re modeling. In my experience, applying DCV to some system types results in hourly OA flow that’s not responding to your OA-FLOW/PER and OA-FLOW/AREA inputs and occupancy levels. In a recent project, I had DCV operating correctly in a VAV system and a Single Zone Reheat system. Try changing your system to either of those types as a sanity check. Then if it makes sense, go ahead and model your system with that system type. DCV can have a significant impact on your space heating and space cooling, so it is important to get the OA flow sorted out and verified in the hourly report as you are doing. <o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Good luck!<o:p></o:p></span></p><div><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Holt Cutler, EIT, LEED AP BD+C<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><img width=51 height=60 id="Picture_x0020_1" src="cid:image001.jpg@01CD01C2.E2FD0B90" alt="Description: Logo 2"></span><b><i><span style='font-size:8.0pt;color:#1F497D'><o:p></o:p></span></i></b></p><p class=MsoNormal><b><i><span style='font-size:9.0pt;color:#1F497D'>EME Consulting Engineering Group, LLC <o:p></o:p></span></i></b></p><p class=MsoNormal><b><i><span style='font-size:9.0pt;color:#1F497D'>159 West 25<sup>th</sup> Street, 5<sup>th</sup> Floor<o:p></o:p></span></i></b></p><p class=MsoNormal><b><i><span style='font-size:9.0pt;color:#1F497D'>New York, NY 10001<o:p></o:p></span></i></b></p><p class=MsoNormal><b><i><span style='font-size:9.0pt;color:#1F497D'>tel: 212-529-5969<o:p></o:p></span></i></b></p><p class=MsoNormal><b><i><span style='font-size:9.0pt;color:#1F497D'><a href="http://www.emegroup.com/">www.EMEgroup.com</a><o:p></o:p></span></i></b></p><p class=MsoNormal><span style='color:#1F497D'> <o:p></o:p></span></p></div><p class=MsoNormal><span style='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>Molly Curtz<br><b>Sent:</b> Tuesday, March 13, 2012 5:19 PM<br><b>To:</b> equest-users@lists.onebuilding.org<br><b>Subject:</b> [Equest-users] DCV-RETURN-SENSOR, Hourly zone OA CFM for SCV Calculation<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Hi All, <o:p></o:p></p><p class=MsoNormal>I’m modeling a system with DCV set to “DCV-RETURN-SENSOR.” The help file says: “The program calculates the OA minimum requirement and sets the minimum damper position hourly based upon the sum of the ZONE requirements. Each zone OA requirement is calculated based upon the hourly maximum of either OA-CFM/PER (times the NUMBER-OF-PEOPLE adjusted by the hourly PEOPLE-SCHEDULE) or a minimum OA ventilation rate.” <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>However, when I look at the hourly report for the zone, “Hourly zone OA CFM requirement for DCV calculation (cfm)” (Var 100), the CFM does not increase for high occupancy hours. My hand calculations show that when I multiply the OA-CFM/PER by the hourly occupancy, it should exceed the minimum OA ventilation rate for the zone (which I specified using OA-FLOW/AREA.)<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I have set the zone minimum flow ratios to “DCV-RESET-UP/DOWN” and the zone minimum flow is increasing according to the occupancy. <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Why is the zone OA CFM requirement not increasing with occupancy? Any thoughts are appreciated.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thanks very much.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Kind regards,<o:p></o:p></p><p class=MsoNormal>Molly<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Times New Roman","serif"'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;font-family:"Times New Roman","serif"'><o:p> </o:p></span></p><p class=MsoNormal><b><span style='font-family:"Times New Roman","serif";color:#28AAE1'>Molly Curtz<o:p></o:p></span></b></p><p class=MsoNormal style='text-align:justify'><span style='font-size:10.0pt;font-family:"Times New Roman","serif";color:#595959'>Mechanical Engineer<o:p></o:p></span></p><p class=MsoNormal style='text-align:justify;text-indent:.5in'><span style='font-size:10.0pt;font-family:"Times New Roman","serif";color:#595959'><o:p> </o:p></span></p><p class=MsoNormal style='text-align:justify'><b><span style='font-family:"Times New Roman","serif";color:#595959'>Arup<o:p></o:p></span></b></p><p class=MsoNormal style='text-align:justify'><span style='font-size:10.0pt;font-family:"Times New Roman","serif";color:#595959'>403 Columbia Street Suite 220 Seattle WA 98104<o:p></o:p></span></p><p class=MsoNormal style='text-align:justify'><b><span style='font-size:10.0pt;font-family:"Times New Roman","serif";color:#595959'>t</span></b><span style='font-size:10.0pt;font-family:"Times New Roman","serif";color:#595959'> +1 206 749 9674 <b>d</b> +1 206 493 2234 <o:p></o:p></span></p><p class=MsoNormal style='text-align:justify'><b><span style='font-size:10.0pt;font-family:"Times New Roman","serif";color:#595959'>f</span></b><span style='font-size:10.0pt;font-family:"Times New Roman","serif";color:#595959'> +1 206 749 0665 <b><o:p></o:p></b></span></p><p class=MsoNormal style='text-align:justify'><span style='font-size:10.0pt;font-family:"Times New Roman","serif";color:#595959'><a href="http://www.arup.com">www.arup.com</a><o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Courier New"'>____________________________________________________________<br>Electronic mail messages entering and leaving Arup business<br>systems are scanned for acceptability of content and viruses</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p></div></body></html>