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<DIV><div class=WordSection1><p class=MsoNormal><span style='color:#1F497D'>Thanks for the suggestions. It appears that the MIN-FLOW-RATIO is overriding the heating flow rates even though the documentation doesn’t make that clear.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Because of the occupancy pattern of my building, the majority of the occupied hours are in the heating season so I have set the supply CFM to be the heating CFM rather than the cooling CFM as a workaround for now.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><div><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif";color:#1F497D'>Todd Gibson<o:p></o:p></span></b></p></div><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><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"'> Nick Caton [mailto:ncaton@smithboucher.com] <br><b>Sent:</b> Wednesday, June 20, 2012 4:11 PM<br><b>To:</b> Gibson, Todd; equest-users@lists.onebuilding.org<br><b>Subject:</b> RE: Supply CFM based on heating / cooling mode<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span style='color:#1F497D'>I have a few thoughts/ideas, in no particular order – maybe something here helps:<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'>Note these flow inputs exist for the system and zone level – you could be editing one and looking at results for the other.<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'>I think MIN-FLOW-RATIO (minimum flow ratio) can override the (optional) heating minimum flow input. Required ventilation capacities can override either as well if I’m not mistaken – maybe worth checking.<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'>Just to point out: a MIN-FLOW-RATIO of 1.0 means the flow will go no lower than 100% of what’s specified (or calculated) for SUPPLY-FLOW. Consider carefully if and where that should apply to fans in the system you’re modeling.<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'>Another thought is at least some of these zonal inputs will default to the system’s values if you aren’t specifying them separately… perhaps your central system is in cooling, using 1.00, while your terminal units are in heating and you end up with a conflict?<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'>~Nick<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><div><p class=MsoNormal><span style='color:#1F497D'><img alt="cid:489575314@22072009-0ABB" height=37 id="Picture_x0020_1" src="cid:image001.jpg@01CD5098.A0A19ED0" width=119></span><b><span style='font-family:"Stylus BT";color:#2D4D5E'><o:p></o:p></span></b></p><p class=MsoNormal><b><span style='font-family:"Stylus BT";color:#2D4D5E'><o:p> </o:p></span></b></p><p class=MsoNormal><b><span style='font-size:12.0pt;font-family:"Stylus BT";color:#2D4D5E'>NICK CATON, P.E.<o:p></o:p></span></b></p><p class=MsoNormal><span style='font-size:7.5pt;color:#CC9900'>SENIOR ENGINEER<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:7.5pt;color:#CC9900'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;color:#2D4D5E'>Smith & Boucher Engineers</span><span style='font-size:7.5pt;font-family:"Times New Roman","serif";color:#CC9900'><o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;color:#2D4D5E'>25501 west valley parkway, suite 200<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;color:#2D4D5E'>olathe, ks 66061<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;color:#2D4D5E'>direct 913.344.0036<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:10.0pt;color:#2D4D5E'>fax 913.345.0617<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><a href="www.smithboucher.com" title="blocked::www.smithboucher.com"><span style='font-size:10.0pt'>www.smithboucher.com</span></a></span><u><span style='font-size:10.0pt;color:blue'> </span></u><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"'> <a href="mailto:equest-users-bounces@lists.onebuilding.org">equest-users-bounces@lists.onebuilding.org</a> <a href="mailto:[mailto:equest-users-bounces@lists.onebuilding.org]">[mailto:equest-users-bounces@lists.onebuilding.org]</a> <b>On Behalf Of </b><a href="mailto:ToddGibson@Eaton.com">ToddGibson@Eaton.com</a><br><b>Sent:</b> Tuesday, June 19, 2012 10:27 AM<br><b>To:</b> <a href="mailto:equest-users@lists.onebuilding.org">equest-users@lists.onebuilding.org</a><br><b>Subject:</b> [Equest-users] Supply CFM based on heating / cooling mode<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>Hi,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I’m trying to specify separate, constant CFMs for heating and cooling mode operation (Ex: 5,000 Heating & 7,500 Cooling). <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>The system I created is Variable Air Volume which serves multiple thermal zones.<o:p></o:p></p><p class=MsoNormal>The Fan Flow Parameter MIN-FLOW-RATIO is set to 1.00. I read this as the minimum supply CFM during cooling mode.<o:p></o:p></p><p class=MsoNormal>The Fan Flow Parameter HMAX-FLOW-RATIO = 5000/7000. I read this to be the maximum supply CFM during heating mode.<o:p></o:p></p><p class=MsoNormal>The Fan Flow Parameter HMIN-FLOW-RATIO = 5000/7000 -0.01. I read this to be the minimum supply CFM during heating mode.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>But from the hourly report the CFM supplied, defined by SUPPLY-FLOW = 7,500, is the cooling quantity during heating mode when I would have expected it to be 5,000. As far as I can tell no flows are specified at the zone level that would override it. Any thoughts on things to look at would be greatly appreciated.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thanks, <span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Todd<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p></div></div></DIV></BODY></HTML>