<html><head><style type="text/css"><!-- DIV {margin:0px;} --></style></head><body><div style="font-family:times new roman,new york,times,serif;font-size:10pt">Rosie:<br><br>I tweaked your project. Please see attached files.<br><br>I set the Warehouse Unit minimum flow for heating to .4 and the maximum flow for heating at 1.0<br>I enabled the zone heat as Furnace, cleared your maximum discharge air temperature for heating and entered 20 degrees as the reheat delta T in the air-side tab.<br><br>By the way, the infiltration in the warehouse is very high, as much as 126,120 CFM. Is this correct?<br><br>Anyway, you now have only 17 unmet heating hours for the warehouse and none for the two office areas.<br><br>Regards,<br><br>Paul Diglio<br><br><br><div><br></div><div style="font-family: times new roman,new york,times,serif; font-size: 10pt;"><br><div style="font-family: times new roman,new york,times,serif; font-size: 12pt;"><font face="Tahoma"
size="2"><hr size="1"><b><span style="font-weight: bold;">From:</span></b> Roselin Osser <Rosie@buildingscience.com><br><b><span style="font-weight: bold;">To:</span></b> Paul Diglio <paul.diglio@sbcglobal.net>; equest-users@lists.onebuilding.org<br><b><span style="font-weight: bold;">Cc:</span></b> Brian Fountain <bfountain@greensim.com>; "Bishop, Bill" <wbishop@pathfinder-ea.com><br><b><span style="font-weight: bold;">Sent:</span></b> Mon, January 17, 2011 11:52:17 AM<br><b><span style="font-weight: bold;">Subject:</span></b> RE: [Equest-users] Heating mode stuck at minimum flow rate<br></font><br>
<style><!--
_filtered {font-family:Calibri;panose-1:2 15 5 2 2 2 4 3 2 4;}
_filtered {font-family:Tahoma;panose-1:2 11 6 4 3 5 4 4 2 4;}
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;margin-bottom:.0001pt;font-size:11.0pt;font-family:"sans-serif";}
a:link, span.MsoHyperlink
{color:blue;text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{color:purple;text-decoration:underline;}
p.MsoAcetate, li.MsoAcetate, div.MsoAcetate
{margin:0in;margin-bottom:.0001pt;font-size:8.0pt;font-family:"sans-serif";}
span.BalloonTextChar
{font-family:"sans-serif";}
p.msochpdefault, li.msochpdefault, div.msochpdefault
{margin-right:0in;margin-left:0in;font-size:12.0pt;font-family:"sans-serif";}
span.emailstyle17
{font-family:"sans-serif";color:windowtext;}
span.EmailStyle21
{font-family:"sans-serif";color:#1F497D;}
.MsoChpDefault
{font-size:10.0pt;}
_filtered {margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{}
--></style><div class="WordSection1"><p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);">Hi everyone,</span></p><p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);"> </span></p><p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);">At this point I think the problem has to do with the fact that I have zone reheat specified as “not installed;” I only have furnace heating at the air handling unit. When I add in zone reheat, increased flow in heating mode is enabled. My system is serving a single zone so there isn’t actually any reheat, but maybe putting in furnace heating with furnace reheat is a workaround.</span></p><p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);"> </span></p><p class="MsoNormal"><span style="font-family: "sans-serif";
color: rgb(31, 73, 125);">I’ve attached my .inp and .pd2 files in case anyone wants to take a look; this is the version without zone reheat.</span></p><p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);">I have a reverse-action thermostat and have tried adjusting the throttling range to 4 or 6 but these don’t affect the minimum flow in heating mode. I was using the Memphis, TN TMY3 file.</span></p><p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);"> </span></p><p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);">Thanks for your ideas and suggestions,</span></p><p class="MsoNormal"><span style="font-family: "sans-serif"; color: rgb(31, 73, 125);">Rosie</span></p><div><div style="border-width: 1pt medium medium; border-style: solid none none; border-color: rgb(181, 196, 223) -moz-use-text-color
-moz-use-text-color; padding: 3pt 0in 0in;"><p class="MsoNormal"><b><span style="font-size: 10pt; font-family: "sans-serif";">From:</span></b><span style="font-size: 10pt; font-family: "sans-serif";"> Paul Diglio [mailto:paul.diglio@sbcglobal.net] <br><b>Sent:</b> Monday, January 17, 2011 6:30 AM<br><b>To:</b> Roselin Osser; equest-users@lists.onebuilding.org<br><b>Subject:</b> Re: [Equest-users] Heating mode stuck at minimum flow rate</span></p></div></div><p class="MsoNormal"> </p><div><div><p class="MsoNormal"><span style="font-size: 10pt;">Rosie:<br><br>What is your thermostat throttling range?<br><br>Try 4 degrees and see what happens.<br><br>Paul Diglio</span></p></div><div><p class="MsoNormal"><span style="font-size: 10pt;"> </span></p><div><div class="MsoNormal" style="text-align: center;" align="center"><span style="font-size: 10pt; font-family: "sans-serif";"><hr align="center" width="100%"
size="1"></span></div><p class="MsoNormal" style="margin-bottom: 12pt;"><b><span style="font-size: 10pt; font-family: "sans-serif";">From:</span></b><span style="font-size: 10pt; font-family: "sans-serif";"> Roselin Osser <Rosie@buildingscience.com><br><b>To:</b> equest-users@lists.onebuilding.org<br><b>Sent:</b> Sun, January 16, 2011 9:24:30 PM<br><b>Subject:</b> [Equest-users] Heating mode stuck at minimum flow rate</span><span style="font-size: 12pt; font-family: "serif";"></span></p><div><p class="MsoNormal">Hi folks,</p><p class="MsoNormal"> </p><p class="MsoNormal">I’m modeling a packaged VAV system (PVAVS) serving only one zone. The maximum airflow the unit can provide is 450,000 cfm, which I have entered in as an airflow parameter. The problem is that whenever the system goes into heating mode, the total cfm goes to minimum airflow (observed from hourly output), even when more heating is
needed, so I end up with a lot of underheated hours. The minimum airflow is calculated from the 10% outdoor air ratio I have entered. I have tried adjusting the HMAX-FLOW-RATIO field to allow the heating airflow to go above the minimum if necessary, but the field seems to have no effect. I have a reverse action thermostat in the zone. Anyone else run into this? There must be some other parameter I’m using that is preventing the field from working. Any advice would be appreciated, as I have tried a lot of input variations and none of them allowed the heating minimum flow to increase when more heat is needed. I’m using eQuest 3.64.</p><p class="MsoNormal"> </p><p class="MsoNormal">Thanks for your help!</p><p class="MsoNormal"> </p><p class="MsoNormal">Rosie</p><p class="MsoNormal"> </p><p class="MsoNormal"> </p><p class="MsoNormal"><span style="font-size: 9pt; color: black;">Roselin
Osser, BEMP, LEED AP</span></p><p class="MsoNormal"><span style="font-size: 9pt; color: black;">Building Science Corporation</span></p><p class="MsoNormal"><span style="font-size: 9pt; color: black;">30 Forest Street</span></p><p class="MsoNormal"><span style="font-size: 9pt; color: black;">Somerville, MA 02143</span></p><p class="MsoNormal"><span style="font-size: 9pt; color: black;">978-589-5100 x 5284</span></p><p class="MsoNormal"><span style="font-size: 9pt; color: black;">fax: 978-589-5103</span></p><p class="MsoNormal"><span style="font-size: 9pt; color: black;"> </span></p><p class="MsoNormal"><span style="font-size: 9pt; color: black;">Building Science Corporation<br>Somerville MA | Waterloo ON<br></span><a rel="nofollow" target="_blank" href="http://www.buildingscience.com/"><span style="font-size: 9pt;">www.buildingscience.com</span></a></p><p class="MsoNormal"><span style="font-size: 9pt; color:
black;"> </span></p><p class="MsoNormal"> </p></div></div></div></div></div></div></div>
</div></body></html>