You could use OA from system, give the supply air a temperature schedule, and put the equipment that conditions this air on a separate meter (as there will be only fan energy required, not heating and cooling).<br><br>This, of course, assumes that you know what temperature the air will be coming in at, but leaves everything else the same.<br>
<br>--<br>Karen<br><br><div class="gmail_quote">On Wed, Feb 18, 2009 at 12:33 PM, Demba Ndiaye <span dir="ltr"><<a href="mailto:Demba.Ndiaye@uoit.ca">Demba.Ndiaye@uoit.ca</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div link="blue" vlink="purple" lang="EN-CA">
<div>
<p><span style="font-size: 11pt; color: rgb(31, 73, 125);">A cautionary note here is that changing outside temperature in
the weather file would, among others, change the load seen by the building.</span></p>
<p><span style="font-size: 11pt; color: rgb(31, 73, 125);" lang="EN-US">_____________</span></p>
<p><span style="font-size: 11pt; color: rgb(31, 73, 125);" lang="EN-US">Demba Ndiaye</span></p>
<p><span style="font-size: 11pt; color: rgb(31, 73, 125);"> </span></p>
<div style="border-style: solid none none; border-color: rgb(181, 196, 223) -moz-use-text-color -moz-use-text-color; border-width: 1pt medium medium; padding: 3pt 0in 0in;">
<p><b><span style="font-size: 10pt;" lang="EN-US">From:</span></b><span style="font-size: 10pt;" lang="EN-US"> <a href="mailto:bldg-sim-bounces@lists.onebuilding.org" target="_blank">bldg-sim-bounces@lists.onebuilding.org</a>
[mailto:<a href="mailto:bldg-sim-bounces@lists.onebuilding.org" target="_blank">bldg-sim-bounces@lists.onebuilding.org</a>] <b>On Behalf Of </b>Steve
Mignogna<br>
<b>Sent:</b> Wednesday, February 18, 2009 11:23 AM<br>
<b>To:</b> <a href="mailto:vishnu@kalpakrit.com" target="_blank">vishnu@kalpakrit.com</a><br>
<b>Cc:</b> <a href="mailto:bldg-sim@lists.onebuilding.org" target="_blank">bldg-sim@lists.onebuilding.org</a><br>
<b>Subject:</b> Re: [Bldg-sim] eQuest - Modelling Earth Air Tunnel system</span></p>
</div><div><div></div><div class="Wj3C7c">
<p> </p>
<p style="margin-bottom: 12pt;">Vishnuraj-<br>
<br>
This is very difficult and may not lead to the correct results, but one method
would be to manually edit the weather file. You would need to change the
temperatures so that the outdoor air that is pulled into the system would be at
the temperature of the earthduct preconditioned air. However, I would not
recommend doing this without testing to see how it changes the other aspects of
the simulation.<br>
<br>
I have seen earthducts modeled correctly in both MATLAB and TRNSYS but I have
not successfully modeled it within eQuest.<br>
<br>
-- <br>
Steve Mignogna<br>
Atelier Ten<br>
<br>
<br>
</p>
<div>
<p>On Wed, Feb 18, 2009 at 2:48 AM, Vishnuraj Nair <<a href="mailto:vishnu@kalpakrit.com" target="_blank">vishnu@kalpakrit.com</a>> wrote:</p>
<div>
<div>
<p><span style="font-size: 10pt;" lang="EN-US"> </span><span lang="EN-US"></span></p>
<p><span style="font-size: 10pt;" lang="EN-US">Hi
friends,</span><span lang="EN-US"></span></p>
<p><span style="font-size: 10pt;" lang="EN-US"> </span><span lang="EN-US"></span></p>
<p><span style="font-size: 10pt;" lang="EN-US">I
am trying to model an Earth Air Tunnel (EAT) system that is being used in a
school for passive precooling.</span><span lang="EN-US"></span></p>
<p><span style="font-size: 10pt;" lang="EN-US">During
summer first the air is pre cooled using the EAT and then evaporative cooling
is done before being circulated into the zone.</span><span lang="EN-US"></span></p>
<p><span style="font-size: 10pt;" lang="EN-US">During
monsoon again precooling is done using EAT and then chillers are being used for
further cooling and dehumidification.</span><span lang="EN-US"></span></p>
<p><span style="font-size: 10pt;" lang="EN-US">Does
anyone have any idea as to how to calculate and incorporate the degree of
precooling that is achieved by the EAT into the eQuest model.</span><span lang="EN-US"></span></p>
<p><span style="font-size: 10pt;" lang="EN-US">Any
help would be greatly appreciated. Thanks</span><span lang="EN-US"></span></p>
<p><span style="font-size: 10pt;" lang="EN-US">Vishnuraj
Nair</span><span lang="EN-US"></span></p>
<p><span style="font-size: 10pt;" lang="EN-US">Kalpakrit
Sustainable Environments Pvt. Ltd. </span><span lang="EN-US"></span></p>
<p><span style="font-size: 10pt;" lang="EN-US">New
Delhi</span><span lang="EN-US"></span></p>
<p><span style="font-size: 10pt;" lang="EN-US">Tel:
+91.124.4309490-92 Ext: 312 , Fax: +91.124.4309493</span><span lang="EN-US"></span></p>
<p><span style="font-size: 10pt;" lang="EN-US">E-mail
: <a href="mailto:vishnu@kalpakrit.com" target="_blank">vishnu@kalpakrit.com</a></span><span lang="EN-US"></span></p>
<p><span lang="EN-US"> </span></p>
</div>
</div>
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