<DIV>I typically make a space using the 'box' approach having side lengths equal to the square root of the floor area to be served by the MAU. Do not add any other details to this space but make it conditioned.</DIV>
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<DIV>Next, make a thermal zone for the space. Under the zone properties, add the outside air requirement plus the schedule you would otherwise use to model ventilation requirement. Give the zone the temperature schedules you are giving to the real spaces. This approach assumes that the MAU is being controlled to provide 'neutral' air to the zones being served and that there is no impact on the zones from the ventilation air system. You have to be careful about not generating ghost reheat penalties or cooling savings.</DIV>
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<DIV>Go into the zones for the actual spaces and configure the "OA cfm" or the OA cfm/person" values as you would normally do. Under the systems section, make the OA from System assignment to your MAU. For residential modeling where WLHPs or PTACs are used, I tend to zero out the outside air assigment for the actual zones and assume that all exhaust and makeup cooling/heating loads and exhaust fan energies take place in the MAU ghost zone. Dividing kitchen appliance energy consumption into space loads and exhausted heat can be tricky, and definitely needs to be done if you are modeling exhaust energy recovery.</DIV>
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<DIV>Maybe somebody else can comment on this, but it seems to me that eQuest cannot properly calculate the total outside air requirement in an MAU system if DCV is used in any zone served by a system served by an MAU. It seems that this needs to be modeled by changing the OA minimum flow schedule, which should agree with the occupancy schedule and the OA/person assumptions. </DIV>
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<DIV>I hope this is helpful. Perhaps others have a better way to do this?</DIV>
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<DIV>Eric</DIV>
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<DIV>__________________<BR><BR>Eric Studer, PE<BR>Project Manager<BR>DMI<BR>35 Walnut Street<BR>Wellesley, MA<BR>(781) 431-1100 ext 12<BR>Fax: (781) 431-1109<BR><BR><BR></DIV>
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<TD>-------Original Message-------<BR>From: Erik Weiss <EW0187@GMAIL.COM><BR>To: equest-users@lists.onebuilding.org<BR>Subject: [Equest-users] MAU: Dummy Zone<BR>Sent: Nov 10 '10 15:27<BR><BR>I need to create a a dummy zone for a MAU. The building is Core and Shell, and only the areas maintained by the owner are being modeled with FCU and the remaining spaces (tenant) is modeled as a baseline building, following ASHRAE 90.1 App. G. How do i create a dummy zone for the MAU (around 20,000 CFM)<BR>_______________________________________________<BR>Equest-users mailing list<BR><A style="TEXT-DECORATION: underline" href="http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org" target=_blank _mce_style="text-decoration: underline;" _mce_href="http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org">http://lists.onebuilding.org/listinfo.cgi/equest-users-onebuilding.org</A><BR>To unsubscribe from this mailing list send a blank message to <A style="TEXT-DECORATION: underline" href="http://mbox.dmiinc.com/compose.php?to=EQUEST-USERS-UNSUBSCRIBE@ONEBUILDING.ORG" target=_top _mce_style="text-decoration: underline;" _mce_href="http://mce_host/compose.php?to=EQUEST-USERS-UNSUBSCRIBE@ONEBUILDING.ORG">EQUEST-USERS-UNSUBSCRIBE@ONEBUILDING.ORG</A><BR></TD></TR></TBODY></TABLE>