<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"><head><meta http-equiv=Content-Type content="text/html; charset=iso-8859-1"><meta name=Generator content="Microsoft Word 14 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-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.EmailStyle17
{mso-style-type:personal-compose;
font-family:"Calibri","sans-serif";
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri","sans-serif";}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></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=WordSection1><p class=MsoNormal>Hello all,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Does anyone have any idea how I would model this hybrid HVAC system that I have. I will attempt to explain it as best as I can. If anyone has any ideas about how I could model this, I would greatly appreciate the help. The project is on a college campus with a central plant. For cooling, the system is reusing return water from the central plant that has already circulated to other buildings on the campus loop. Outside air is taken in and cooled first through a heat exchanger, then sent through a pre-cool economizer that uses 55° return water from the central plant to cool the air to 65°. This air is sent through a DX cooling coil and further cooled to 48° and then mixed with return air that has been cooled to 58° also reusing return water from the central plant. All water from the system goes through a water-cooled DX compressor before it is returned back to the central plant. I need to figure out how to best model this in eQuest to account for the reuse of the return water if this is even possible. The only way we could think to model it would be to model a water source heat pump on the cooling side and the district loop on the heating side, but this does not account for the reuse of the return water. If anyone has any thoughts, I would really appreciate it.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Thanks,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Jason Cocek, LEED AP O+M<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>