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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">I am having some difficulty setting up multiple HVAC systems serving one zone.
<br>
The situation is that I am modeling a building with packaged rooftop units as<br>
well as exhaust fans. However, I can't model the exhaust fans using the exhaust<br>
fan object because the exhaust fans are controlled based on enthalpy<br>
differential with outdoor air (as I understand it, exhaust fan availability<br>
managers only allow temperature differential).<br>
<br>
So I thought I would set up another HVAC system in addition to the RTUs that<br>
would function like the exhaust fans (with a supply fan, rather than exhaust, no<br>
heating or cooling coils). I could then use an outside air controller to<br>
specify the enthapy differential control. The issue I am having is setting up<br>
both systems to serve one zone. Do I connect the second system (exhaust<br>
system)to the zone inlet node, or upstream of the zone splitter associated with<br>
the RTUs? Where do I connect downstream of the zone?<br>
<br>
Any help would be much appreciated. Of course, if anyone has a way of getting<br>
the exhaust fan object to run on differential enthalpy, I would take suggestions<br>
there too!!<br>
<br>
Andrew</span><o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal" style="margin-bottom:6.0pt"><a href="http://www.environcorp.com/"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:black;text-decoration:none"><img border="0" width="120" height="26" id="Picture_x0020_5" src="cid:image003.jpg@01CDCBEC.967765A0"></span></a><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:black"><o:p></o:p></span></p>
<p class="MsoNormal"><b><span style="font-family:"Arial","sans-serif";color:black">Andrew Sheaffer, PE, CPEnMS, CEM</span></b><b><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:black"> |
</span></b><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:black">Manager, Carbon and Energy</span><span style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#595959">ENVIRON International Corporation<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#595959">333 W. Wacker | Suite 2700 | Chicago, IL 60606<br>
T: +1 312 288 3897 | F: +1 312 288 3801 | M: +1 312 731 7096<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:#595959"><a href="mailto:asheaffer@environcorp.com"><span style="color:#595959;text-decoration:none">asheaffer@environcorp.com</span></a>
<o:p></o:p></span></p>
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