<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"
xmlns:ns0="urn:schemas-microsoft-com:office:smarttags">
<head>
<meta http-equiv=Content-Type content="text/html; charset=us-ascii">
<meta name=Generator content="Microsoft Word 12 (filtered medium)">
<style>
<!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
span.apple-style-span
{mso-style-name:apple-style-span;}
span.EmailStyle18
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;}
@page Section1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.Section1
{page:Section1;}
-->
</style>
<!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang=EN-US link=blue vlink=purple>
<div class=Section1>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Something interesting that I noticed with your model (that is
sort of besides the point): most of your PIU systems have ~ 2600+ hrs
when the zones are undercooled, yet your BEPS report only shows 7.5% hours
unmet load hours….interesting.<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'>To the actual problem at hand: it would appear your
chilled water and condenser water loops use the SAME reset schedule…this
can’t be right, can it? You’re basically forcing your heat
rejection loop to be at 63 degrees during the summer, which is why you have
such high heat rejection power consumption #s.<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'>Maybe fix that first?<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:11.0pt;font-family:"Arial","sans-serif";
color:teal'>GHT Limited<br>
</span></b><b><span style='font-size:11.0pt;font-family:"Arial","sans-serif"'><ns0:PersonName><span
style='color:black'>James Hansen</span></ns0:PersonName></span></b><b><span
style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:black'>, PE,
LEED AP<o:p></o:p></span></b></p>
<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:black'>Senior Associate</span></b><b><span style='font-size:11.0pt;
font-family:"Calibri","sans-serif";color:black'><o:p></o:p></span></b></p>
<p class=MsoNormal><span style='font-size:7.5pt;font-family:"Arial","sans-serif"'><ns0:Street><ns0:address><span
style='color:black'>1010 N. Glebe Rd, Suite 200</span></ns0:address></ns0:Street></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:7.5pt;font-family:"Arial","sans-serif"'><ns0:place><ns0:City><span
style='color:black'>Arlington</span></ns0:City><span style='color:black'>, </span><ns0:State><span
style='color:black'>VA</span></ns0:State><span style='color:black'> </span><ns0:PostalCode><span
style='color:black'>22201-4749</span></ns0:PostalCode></ns0:place></span><span
style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:black'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:7.5pt;font-family:"Arial","sans-serif";
color:black'>703-338-5754 (Cell)</span><span style='font-size:11.0pt;
font-family:"Calibri","sans-serif";color:black'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:7.5pt;font-family:"Arial","sans-serif";
color:black'>703-243-1200 (Office)</span><span style='font-size:11.0pt;
font-family:"Calibri","sans-serif";color:black'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:7.5pt;font-family:"Arial","sans-serif";
color:black'>703-276-1376 (Fax)</span><span style='font-size:11.0pt;font-family:
"Calibri","sans-serif";color:black'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Arial","sans-serif";
color:teal'><a href="http://www.ghtltd.com/"><span style='font-size:10.0pt;
color:blue'>www.ghtltd.com</span></a><o:p></o:p></span></p>
<p class=MsoNormal><b><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#31849B'><o:p> </o:p></span></b></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"'> equest-users-bounces@lists.onebuilding.org
[mailto:equest-users-bounces@lists.onebuilding.org] <b>On Behalf Of </b>Mike
Hall<br>
<b>Sent:</b> Monday, April 05, 2010 7:12 PM<br>
<b>To:</b> equest-users@lists.onebuilding.org<br>
<b>Subject:</b> [Equest-users] CW Loop reset<o:p></o:p></span></p>
</div>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><span class=apple-style-span><span style='font-family:"Arial","sans-serif";
color:black'>Hi All,<o:p></o:p></span></span></p>
<div>
<p class=MsoNormal><o:p> </o:p></p>
</div>
<div>
<p class=MsoNormal><span style='font-family:"Arial","sans-serif";color:black'>I
am modeling a VAV system using water cooled DX air handlers on four of five
floors. 24/7 load spaces use CHW fan coil units and the entire fourth
floor uses chilled water VAV air handler. Each DX VAV has an economizer
coil so hours in the winter when the CW temp is low enough the internal zone
receives free cooling. The entire chilled water loop also has a
water-side economizer so all the chilled water equipment can recieve free
cooling.<o:p></o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-family:"Arial","sans-serif";color:black'><o:p> </o:p></span></p>
</div>
<div>
<p class=MsoNormal><span style='font-family:"Arial","sans-serif";color:black'>As
seen by the elec consumption graphs I'm having a problem with the CW loop
control strategy. Either the loop operates at the commanded setpoint of
85 deg. Which means there is no free cooling. Or when I try to use
OA-Reset the cooling loads during the winter are met via free-cooling but
during the summer the chiller barely runs and the cooling tower tries to meet
the load of the CHW loop.<br>
<br>
I was able to find the way to disable the error caused by condenser water below
65 deg thanks to post from board veterans like Mike TIllou, Steve Gates, John
Albach, and others). I do not know what else to try.<br>
<br>
Thanks,<br>
MH<o:p></o:p></span></p>
</div>
</div>
</body>
<!--[object_id=#ghtltd.com#]--><P align=left><FONT size=2><FONT face=Tahoma><FONT color=#0000ff>
<HR>
</FONT></FONT><FONT color=#0000ff><FONT color=#000000><FONT face=Arial>The information contained in this communication is confidential, may be privileged, and is intended only for the use of the addressee. It is the property of GHT Limited. Unauthorized use, disclosure or copying of this communication or any part thereof is strictly prohibited and may be unlawful. If you have received this communication in error, please notify me immediately by return e-mail or by e-mail to </FONT><A href="mailto:ght@ghtltd.com"><FONT face=Arial>ght@ghtltd.com</FONT></A><FONT face=Arial>, and destroy this communication and all copies thereof, including all attachments. Thank you.</FONT></FONT><FONT face=Tahoma color=#000000></FONT></P></FONT></FONT></html>