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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Here is what I am having problems with in eQuest. The
perimeter system which I am trying to model is fan coils served by an outside
ventilation unit. The outside ventilation unit is constant volume but has an
outside air economizer (i.e. minimum outside air is 25% and max is 100%, but a
constant 33,000 cfm through the fan). It supplies the fan coils with a constant
volume of air but this primary air can be any mixture of OA from 25% to 100%
based on the ventilation unit economizer. The fan coils have constant volume
fans but re-circulate about 85% of the room (secondary) air.</span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> </span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>I have made each fan coil its own system serving the
corresponding thermal zone. Then I have used the <b><span style='font-weight:
bold'>outside air from other system command</span></b> to bring in primary air
from the ventilation unit on which I have placed the dual enthalpy economizer.
I have had to add a fake zone b/c the model will not run if the main
ventilation unit is not serving at least one conditioned zone. </span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> </span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>After running hourly reports on the ventilation unit I have
noticed it never economizes, therefore it brings in the minimum 8250 cfm year
around which is 25% of 33000. With hourly reports of the space I noticed there
were cooling loads during the winter when this unit should be economizing but
was not. I have changed every setpoint for the main ventilation unit’s
economizer and have even changed it to dual-temp with a low limit of 0F to a
high of 100F and it still will not economize throughout the year. So I am
stumped, thanks for your help.</span></font></p>
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font-family:Arial'> </span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'> </span></font></p>
<p class=MsoNormal><strong><b><font size=3 face=Arial><span style='font-size:
12.0pt;font-family:Arial'>Joshua D. Wolfe, </span></font></b></strong><em><b><i><font
face=Arial><span style='font-family:Arial;font-weight:bold'>EIT</span></font></i></b></em></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Project Engineer</span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Geo-Marine, Inc. Energy Services</span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>146 Market Place Boulevard</span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Phone: 865.692.0084 ext. 216</span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Fax: 865.692.0560</span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>jwolfe@geo-marine.com</span></font></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'> </span></font></p>
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